Document:

Exhibit 10.1

 

Execution

FIRST
AMENDMENT TO

SECOND
AMENDED AND RESTATED CREDIT AGREEMENT

THIS FIRST AMENDMENT TO
SECOND AMENDED AND RESTATED CREDIT AGREEMENT (this “Amendment”) is
entered into as of February 16, 2007, among MARKWEST HYDROCARBON, INC., a Delaware
corporation, as borrower (the “Borrower”), the undersigned Guarantors (collectively,
the “Guarantors”),
ROYAL BANK OF CANADA, as Administrative Agent and Collateral Agent for the
Lenders parties to the hereinafter defined Credit Agreement (in its capacity as
administrative agent, the “Administrative
Agent” and in its capacity as collateral agent, the “Collateral Agent”), and the
undersigned L/C Issuer and Lenders.

Reference is made to the
Second Amended and Restated Credit Agreement dated as of August 18, 2006 among
Borrower, the Administrative Agent, the Collateral Agent, the L/C Issuer and
the Lenders parties thereto (the “Credit Agreement”).  Unless otherwise defined in this Amendment,
capitalized terms used herein shall have the meanings set forth in the Credit
Agreement; all section and schedule references herein are to sections and
schedules in the Credit Agreement; and all paragraph references herein are to
paragraphs in this Amendment.

RECITALS

A.                                    The Borrower has requested that the Credit
Agreement be amended to provide for a new non-borrowing base (NBB) revolving
credit facility of up to $50,000,000, the sole purpose of which is to enable
the Borrower to meet margin requirements associated with Swap Contracts, which
revolving credit facility may be requested by the Borrower and which each
Lender may decide to participate in or not in such Lender’s sole and absolute
discretion.

B.                                    Subject to the terms and conditions of this
Amendment, the Administrative Agent and the other Lenders are willing to agree
to such amendment.

Accordingly, for adequate
and sufficient consideration, the parties hereto agree, as follows:

Paragraph 1.                     Amendments. Effective as of the First Amendment
Effective Date, the Credit Agreement is amended as follows:

1.1                               Definitions. Section
1.01 of the Credit
Agreement is amended as follows:

(a)                                  Each of the following definitions is amended
in its entirety to read as follows:

“Applicable Rate means (a) with respect to the Revolving
Credit Facility, the following amounts per annum set forth in the table below,
on any date of determination, with respect to the Type of Credit Extension or
commitment fee that corresponds to the Utilization Percentage at such date of
determination:

 1
 

Revolving Credit
Commitment and Revolving Credit Loans and Letters of Credit

	
  Pricing

  Level

  	
   

  	
  Revolving

  Credit

  Utilization

  Percentage

  	
   

  	
  Letter of Credit and

  Eurodollar Rate

  + (bps)*

  	
   

  	
  Base Rate + (bps)*

  	
   

  	
  Revolving Credit

  Commitment Fee

  + (bps)

  
	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  
	
  1

  	
   

  	
  Less than 50%

  	
   

  	
  150.0

  	
   

  	
  50.0

  	
   

  	
  37.5

  
	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  
	
  2

  	
   

  	
  50% or more but less than 75%

  	
   

  	
  200.0

  	
   

  	
  100.0

  	
   

  	
  50.0

  
	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  
	
  3

  	
   

  	
  75% or more but less than 100%

  	
   

  	
  250.0

  	
   

  	
  150.0

  	
   

  	
  50.0

  
	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  
	
  4

  	
   

  	
  100% or more

  	
   

  	
  275.0

  	
   

  	
  175.0

  	
   

  	
  50.0

  

 

*Upon the first to occur of (i) outstanding Revolving Credit Loans and
Outstanding Amount of L/C Obligations exceeding in the aggregate $40,000,000
under the Aggregate Revolving Credit Commitment after it has been increased
pursuant to Section 2.13, or (ii) there
being outstanding NBB Revolving Credit Loans pursuant to Section
2.15, and thereafter for each day that the conditions specified
in clauses (i) and/or (ii) above continue to exist, the Applicable Rate for
Revolving Credit Loans and Letters of Credit (but not the Revolving Credit
Commitment Fee which remains unchanged) will be increased by 0.50% per annum
(50 basis points) over the amounts set forth above.

(b)  with
respect to the Unit Acquisition Facility, the Applicable Rate for Eurodollar
Rate Loans shall be the sum of the Eurodollar Rate plus 350 bps, the Applicable
Rate for Base Rate Loans shall be the sum of the Base Rate plus 250 bps and for
the Unit Acquisition Commitment Fee, 50 bps.

(c) with respect to the NBB
Revolving Credit Facility, the Applicable Rate for Eurodollar Rate Loans shall
be the sum of the Eurodollar Rate plus 325 bps, the Applicable Rate for Base
Rate Loans shall be the sum of the Base Rate plus 225 bps, the Applicable Rate
for NBB Letters of Credit shall be 325 bps, and for the NBB Revolving Credit
Commitment Fee, 50 bps.

“Agreement
means this Second Amended and Restated Credit Agreement as amended by the First
Amendment to Credit Agreement.”

“Borrowing means, as the context may
require, a Revolving Credit Borrowing, a Unit Acquisition Borrowing, a NBB
Revolving Credit Borrowing or any combination thereof and “Borrowings”
means all Revolving Credit Borrowings, Unit Acquisition Borrowings, NBB
Revolving Credit Borrowings or any combination thereof.”

“Cash Collateralize means to pledge and deposit with or deliver
to the Administrative Agent, for the benefit of the L/C Issuer and the Lenders,
as collateral for the L/C Obligations (or for the benefit of the NBB L/C Issuer
and the Lenders having a NBB Revolving Credit Commitment for the tranche for
which a NBB Letter of Credit was issued and which is being Cash
Collateralized), cash and deposit account balances

 2
 

pursuant to documentation in form and substance satisfactory to the
Administrative Agent and (i) in the case of Letters of Credit, the L/C Issuer
(which documents hereby are consented to by the Lenders), and (ii) in the case
of NBB Letters of Credit, the NBB L/C Issuer (which documents are hereby
consented to by the Lenders having a NBB Revolving Credit Commitment).”

“Commitment means as to any Lender,
as the context may require, its Revolving Credit Commitment, its Unit Acquisition
Commitment, its NBB Revolving Credit Commitment (provided such Lender has
agreed to participate in NBB Revolving Credit Loans pursuant to Section 2.15 and then only to the
extent such Lender has specifically agreed to participate in NBB Revolving Credit
Loans) or any combination thereof and as to all Lenders, as the context may
require, the Aggregate Revolving Credit Commitment, the Aggregate Unit
Acquisition Commitment, the Aggregate NBB Revolving Credit Commitment or any
combination thereof.”

“Lender has the meaning specified in the
introductory paragraph hereto and, as the context requires, includes the L/C
Issuer and NBB L/C Issuer.”

“Letter of Credit means the Existing Letter of Credit and any
standby letter of credit issued pursuant to Section
2.14.”

“Letter of Credit Application means an application and agreement for the
issuance or amendment of a letter of credit in the form from time to time in
use by the L/C Issuer or NBB L/C Issuer.”

“Loan means, as the context
may require, a Revolving Credit Loan, a Unit Acquisition Loan, a NBB Revolving
Credit Loan or any combination thereof and “Loans”
means all Revolving Credit Loans, Unit Acquisition Loans, NBB Revolving Credit
Loans or any combination thereof.”

“Maturity Date means (a) the Stated Maturity Date or (b)
such earlier effective date of any other termination, cancellation, or
acceleration of the Aggregate Revolving Credit Commitment and/or Aggregate Unit
Acquisition Commitment and/or Aggregate NBB Revolving Credit Commitment under
this Agreement.”

“Note means, as the context
may require, a Revolving Credit Note, a Unit Acquisition Note, a NBB Revolving
Credit Note or any combination thereof and “Notes”
means all Revolving Credit Notes, Unit Acquisition Notes, NBB Revolving Credit
Notes or any combination thereof.”

“Obligations means all advances to, and debts,
liabilities, obligations, covenants and duties of, any Loan Party arising under
any Loan Document, whether direct or indirect (including those acquired by
assumption), absolute or contingent, due or to become due, now existing or
hereafter arising and including interest that accrues after the commencement by
or against any Loan Party of any proceeding under any Debtor Relief Laws naming
such Person as the debtor in such proceeding. In addition, all references to
the “Obligations” in
the Collateral Documents and in Sections 2.16 and 10.09 of this Agreement shall, in addition to
the foregoing, also include all present and future indebtedness, liabilities,
and obligations (and all renewals and extensions thereof or any

 3
 

part
thereof) now or hereafter owed to any Lender or any Affiliate of a Lender
arising pursuant to any Lender Hedging Agreement.”

“Outstanding Amount on any date (i) with respect to Loans, means
the aggregate principal amount thereof after giving effect to any Borrowings
and prepayments or repayments occurring on such date, (ii) with respect to any
L/C Obligations, the amount of such L/C Obligations on such date after giving
effect to any L/C Credit Extension occurring on such date and any other changes
in the aggregate amount of the L/C Obligations as of such date, including as a
result of any reimbursements of outstanding unpaid drawings under any Letters
of Credit or any reductions in the maximum amount available for drawing under
Letters of Credit taking effect on such date, and (iii) with respect to any NBB
L/C Obligations, the amount of such NBB L/C Obligations on such date after
giving effect to any NBB L/C Credit Extension occurring on such date and any
other changes in the aggregate amount of the NBB L/C Obligations as of such
date, including as a result of any reimbursements of outstanding unpaid
drawings under any NBB Letters of Credit or any reductions in the maximum
amount available for drawing under NBB Letters of Credit taking effect on such
date.”

“Request for Credit Extension means (a) with respect to a Borrowing,
conversion or continuation of Loans, a Borrowing Notice, and (b) with respect
to an L/C Extension or NBB L/C Extension, a Letter of Credit Application.”

 “Required Lenders means on any date of determination on and
after the Second Restatement Date and prior to the Maturity Date, those Lenders
holding more than 66 2/3% of the sum of (i) the Aggregate Revolving Credit
Commitment plus (ii) the Aggregate Unit Acquisition Commitment plus (iii) the
Aggregate NBB Revolving Credit Commitment, if any, and on any date of
determination on or after the Maturity Date, those Lenders holding more than 66
2/3% of the sum of (x) the Outstanding Amount of Revolving Credit Loans plus
(y) the Outstanding Amount of L/C Obligations plus (y) the Outstanding Amount
of Unit Acquisition Loans plus (z) the Outstanding Amount of NBB Revolving
Credit Loans.”

“Stated Maturity Date means
August 20, 2010.”

(b)                                 The following definitions are inserted
alphabetically into Section
1.01 of the Credit Agreement:

“Aggregate NBB Revolving Credit Commitment
has the meaning specified in the definition of NBB
Revolving Credit Commitment.”

“First Amendment
Effective Date means the date the First Amendment to Credit
Agreement by its terms becomes effective among the parties thereto.”

“First Amendment to Credit Agreement means that certain
First Amendment to Second Amended and Restated Credit Agreement dated as of
February 16, 2007, among the Borrower, the Guarantors, Royal Bank of Canada, as
Administrative Agent and Collateral Agent, the L/C Issuer and the Lenders.”

“Lender Hedging Agreement means a Swap Contract between the Borrower
or any of the MarkWest Inc. Subsidiaries and a Lender or an Affiliate of a
Lender.”

 4
 

“NBB Borrowing Certificate means, a  certificate
in the form attached hereto as Exhibit F,
appropriately completed.”

“NBB Credit Extension means each of the following: (a) a NBB
Revolving Credit Borrowing and (b) a NBB L/C Credit Extension.”

“NBB Evergreen Letter of Credit has the meaning specified in Section 2.16(b)(iii).”

“NBB Honor Date has the meaning set forth in Section 2.16(c)(i).”

“NBB L/C Advance means, with respect to each Lender having a
NBB Revolving Credit Commitment for the tranche for which a NBB Letter of
Credit was issued, such Lender’s participation in any NBB L/C Borrowing in
accordance with its percentage participation in such NBB Letter of Credit in an
amount equal to the product of such Lender’s participation percentage in that
tranche of the NBB Revolving Credit Commitment times
the amount of such NBB L/C Advance.”

“NBB L/C Borrowing means an extension of credit resulting from
a drawing under any NBB Letter of Credit which has not been reimbursed on the
date when made or refinanced as a NBB Revolving Credit Borrowing.”

“NBB L/C Credit Extension means, with respect to any NBB Letter of
Credit, the issuance thereof or extension of the expiry date thereof, or the
renewal or increase of the amount thereof.”

“NBB L/C Issuer means Royal Bank of Canada in its capacity
as issuer of NBB Letters of Credit hereunder, or any successor issuer of NBB
Letters of Credit hereunder.”

“NBB L/C Obligations means, as at any date of determination, the
aggregate undrawn face amount of all outstanding Letters of Credit plus the aggregate of all Unreimbursed
Amounts, including all L/C Borrowings.”

“NBB Letter of Credit means any standby letter of credit issued
pursuant to Section 2.16.

“NBB  Letter of Credit Expiration Date means the day that is five days prior to the
Maturity Date (or, if such day is not a Business Day, the next preceding
Business Day).”

“NBB Letter of Credit Sublimit means with respect to each tranche of the
NBB Revolving Credit Commitment, an amount equal to the amount of such tranche.”

“NBB Nonrenewal Notice Date has the meaning specified in Section 2.16(b)(iii).”

 5
 

“NBB Pro Rata Share means, at any date of determination, for any
Lender having a NBB Revolving Credit Commitment, the percentage (carried out to
the ninth decimal place) that its NBB Revolving Credit Commitment bears to the
Aggregate NBB Revolving Credit Commitment.”

“NBB Revolving Credit Borrowing means a borrowing consisting of simultaneous
NBB Revolving Credit Loans of the same Type and having the same Interest Period
made by each of the Lenders having a NBB Revolving Credit Commitment pursuant
to Section 2.15(f),
the sole purpose of which borrowing is to enable the Borrower to meet margin
requirements under Swap Contracts.

“NBB Revolving Credit Commitment means, as to each Lender which agrees to
participate in making NBB Revolving Credit Loans (or to participate in any
requested increase of the NBB Revolving Credit Commitment) pursuant to Section 2.15, its obligation to make
NBB Revolving Credit Loans to the Borrower pursuant to Section 2.15(f),  and to purchase
participations in NBB L/C Obligations pursuant to Section 2.16, in an aggregate
principal amount at any one time outstanding not to exceed the amount stated
beside such Lender’s name under the column headed “NBB Revolving Credit
Commitment” on Schedule
2.01 (which amount is subject to increase, reduction, or
cancellation in accordance with the Loan Documents), as supplemented from time
to time (collectively, the NBB Revolving Credit Commitments of all the Lenders
herein having a NBB Revolving Credit Commitment the “Aggregate NBB Revolving Credit  Commitment”).”

“NBB Revolving Credit Commitment
Effective Date has the meaning set forth in Section 2.15(d).”

“NBB Revolving Credit Commitment Fee means a fee payable pursuant to Section 2.08(d) to any Lender having
a NBB Revolving Credit Commitment.

“NBB Revolving Credit Commitment
Increase Effective Date has the meaning set forth in Section 2.15(d).”

“NBB Revolving Credit
Facility means the non-borrowing base (NBB) revolving credit
facility as described in and subject to the limitations set forth in Section 2.15, the sole purpose of
which credit facility is to enable the Borrower to meet margin requirements
under Swap Contracts”.

“NBB Revolving Credit Loan means an extension of credit by a Lender
having a NBB Revolving Credit Commitment to the Borrower pursuant to Section 2.15(f), the sole
purpose of which extension of credit is to enable the Borrower to meet margin
requirements under Swap Contracts.”

“NBB Revolving Credit Note means a promissory note of Borrower in
substantially the form of Exhibit
B-3, evidencing the obligation of Borrower to repay the NBB
Revolving Credit Loans and all renewals and extensions of all or any part
thereof.”

“NBB Unreimbursed Amount has the meaning set forth in Section 2.16(c)(i).”

 6
 

 “Required NBB Revolving Credit Lenders means on any date of determination on and
after the NBB Revolving Credit Commitment Effective Date and prior to the
Maturity Date, those Lenders holding more than 66 2/3% of the Aggregate NBB
Revolving Credit Commitment and on any date of determination on or after the
Maturity Date, those Lenders holding more than 66 2/3% of the Outstanding
Amount of NBB Revolving Credit Loans.”

(c)                                  Section
2.03(a) of the Credit Agreement is amended by deleting
the fifth sentence thereof and substituting therefor the following:

“Each
Borrowing Notice (whether telephonic or written) shall specify (i) whether the
Borrower is requesting a Borrowing, a conversion of Loans from one Type to the
other, or a continuation of Loans as the same Type, (ii) the requested date of
the Borrowing, conversion or continuation, as the case may be (which shall be a
Business Day), (iii) the principal amount of Loans to be borrowed, converted or
continued and if a Borrowing, whether such Loans are Revolving Credit Loans or
Unit Acquisition Loans or NBB Revolving Credit Loans, (iv) the Type of Loans to
be borrowed or to which existing Loans are to be converted, and (v) if
applicable, the duration of the Interest Period with respect thereto.”

(d)                                 Section
2.03(b) of the Credit Agreement is amended by deleting
the first sentence thereof and substituting therefor the following:

“Following
receipt of a Borrowing Notice, the Administrative Agent shall promptly notify
each Lender of its Pro Rata Share of the applicable Borrowing (or in the case
of a NBB Revolving Credit Borrowing, each Lender having a NBB Revolving Credit
Commitment shall be notified of its NBB Pro Rata Share), and if no timely
notice of a conversion or continuation is provided by the Borrower, the
Administrative Agent shall notify each Lender of the details of any automatic
conversion to Base Rate Loans described in the preceding subsection.”

(e)                                  Section
2.04(a) of the Credit Agreement is deleted in its
entirety and the following is substituted therefor:

“(a)                            Optional Prepayments.  The
Borrower may, upon notice to the Administrative Agent, at any time or from time
to time voluntarily prepay in whole or in part Loans outstanding under the
Revolving Credit Facility and/or the Unit Acquisition Facility and/or the NBB
Revolving Credit Facility without premium or penalty; provided that (i) such notice must be
received by the Administrative Agent not later than 11:00 a.m., New York time,
(A) three Business Days prior to any date of prepayment of Eurodollar Rate
Loans, and (B) the date of prepayment of Base Rate Loans; (ii) any prepayment
of Eurodollar Rate Loans shall be in a principal amount of $500,000 or a whole
multiple of $500,000 in excess thereof; and (iii) any prepayment of Base Rate
Loans shall be in a principal amount of $500,000 or a whole multiple of
$100,000 in excess thereof.  Each such
notice shall specify the date and amount of such prepayment and the Type(s) of
Loans to be prepaid.  The Administrative
Agent will promptly notify each Lender of its receipt of each such notice, and
of such Lender’s Pro Rata Share of such prepayment (or NBB Pro Rata Share, if
the NBB Revolving Credit Facility is being prepaid).  If such notice is given by the Borrower, the
Borrower shall make such prepayment and the payment amount specified in such
notice shall be due and payable on the date specified

 7
 

therein.  Any prepayment of a
Eurodollar Rate Loan shall be accompanied by all accrued interest thereon,
together with any additional amounts required pursuant to Section 3.05.  Each such prepayment shall be applied to the
Loans of the Lenders in accordance with their respective Pro Rata Shares (or
NBB Pro Rata Shares, if the NBB Revolving Credit Facility is being prepaid) as
directed by the Borrower or if no such direction is given, first, to the repayment in full of any L/C
Borrowings, second, to the repayment of the Unit
Acquisition Loans, until paid in full, third, to
repayment of the NBB Revolving Credit Loans and fourth,
to repayment of the Revolving Credit Loans.”

“Unless a Default or Event of Default has occurred and is continuing or
would arise as a result thereof, any payment or prepayment of the Revolving
Credit Loans, Unit Acquisition Loans and NBB Revolving Credit Loans may be
reborrowed by Borrower, subject to the terms and conditions hereof.”

(f)                                    Section
2.04(b)(i) of the Credit Agreement is deleted in its
entirety and the following is substituted therefor:

“(i)                                If any portion of the Reduction Amount from
any Triggering Sale (including any deferred purchase price therefor) has not
been Reinvested within one hundred eighty (180) days from the receipt by
Borrower or any other Loan Party of such Reduction Amount (including receipt of
any deferred payments for any such Triggering Sale or portion thereof, if and
when received), then on the Business Day following such one hundred eightieth
(180th) day the Unit Acquisition Loans, the NBB Revolving Credit Loans, if any,
and the Revolving Credit Loans shall be prepaid, in an amount equal to the
portion of the Reduction Amount that is not so Reinvested, as provided in Section 2.04(b)(v).  Net Cash Proceeds from Insurance
Payments and Dispositions that equal, when aggregated with Net Cash Proceeds
from all Insurance Payments and Dispositions since the Second Restatement Date,
an amount less than the Threshold Amount shall not be required to be used for
mandatory prepayments of the Unit Acquisition Loans, the NBB Revolving Credit
Loans, if any, and the Revolving Credit Loans pursuant to Section 2.04(b(v)).”

(g)                                 Section
2.04(b)(ii) of the Credit Agreement is deleted in its
entirety and the following is substituted therefor:

“(ii)                            Upon receipt by any Loan Party of any
Reduction Amount, the Borrower (A) shall deliver a Triggering Sale Certificate
to the Administrative Agent and each Lender pursuant to Section
6.02(e) and (B) shall, or shall cause the applicable Loan Party
to, deposit an amount equal to the Reduction Amount into an account with the
Administrative Agent or another Lender, as elected by the Administrative Agent
(the “Proceeds Account”); provided, however, that the Borrower or such Loan Party
shall not be required to deposit an amount that is more than the sum of the
Aggregate Revolving Credit Commitment plus the
Aggregate Unit Acquisition Commitment plus the
Aggregate NBB Revolving Credit Commitment, if any.  Such Reduction Amount shall remain in the
Proceeds Account until the earliest of (x) the date such Reduction Amount is
Reinvested, (y) the one hundred eightieth (180th)
day following the receipt of such Reduction Amount or (z) the occurrence of an
Event of Default. If such Reduction Amount has been Reinvested within such one
hundred (180) day period as reflected on the Reinvestment Certificate delivered
to the Administrative Agent pursuant to Section 6.02(f),
then the Unit Acquisition Loans, NBB Revolving Credit Loans, if any, and the

 8
 

 

Revolving Credit Loans are not required to be prepaid.  However, if the Reduction Amount has not been
Reinvested within one hundred (180) days following its receipt by any Loan
Party, on the Business Day following such one hundred eightieth (180th) day, the Unit Acquisition Loans, NBB Revolving Credit Loans, if any,
and the Revolving Credit Loans shall be prepaid, in an amount equal to the
portion of the Reduction Amount that is not so Reinvested, as provided in Section 2.04(b)(v); provided, further, that if as the result of an Event of
Default the Revolving Credit Loans, NBB Revolving Credit Loans, if any, and
Unit Acquisition Loans have become due and payable pursuant to Section 8.02 or otherwise, the
Administrative Agent may, without notice, apply all funds in the Proceeds
Account to repayment of the Obligations immediately after the occurrence of
such Event of Default.”

(h)                                 Section
2.04(b)(iii) of the Credit Agreement is deleted in its
entirety and the following is substituted therefor:

“(iii)                         If any Net Cash Proceeds are received by any
Loan Party from an Equity Offering, the Unit Acquisition Loans, NBB Revolving
Credit Loans, if any, and the Revolving Credit Loans shall be prepaid by the
Borrower immediately after receipt of such Net Cash Proceeds, in an amount
equal to the amount of Net Cash Proceeds received by the Borrower or such other
Loan Party from such Equity Offering, as provided in Section 2.04(b)(v).”

(i)                                     Section
2.04(b)(iv) of the Credit Agreement is deleted in its
entirety and the following is substituted therefor:

“(iv)                        If Net Cash Proceeds are received by any Loan
Party from a Senior Debt Offering, the Unit Acquisition Loans, NBB Revolving
Credit Loans, if any, and the Revolving Credit Loans shall be prepaid,
immediately upon receipt of such Net Cash Proceeds, in an amount equal to the
amount of Net Cash Proceeds received by the Borrower or such other Loan Party
from such Senior Debt Offering, as provided in Section 2.04(b)(v).”

(j)                                     Section
2.04(b)(v) of the Credit Agreement is deleted in its
entirety and the following is substituted therefor:

“(v)                           The prepayments provided for in this Section 2.04(b) shall
be applied as follows, unless a
Default or Event of Default has occurred and is continuing or would arise as a
result thereof (whereupon the provisions of Section 2.11(d) shall apply): (A) first, as a repayment of any L/C
Borrowing, (B) second as a repayment of the Unit Acquisition Loan, until paid
in full,  (C) third,
as a repayment of the NBB Revolving Credit Loan,  if any, until paid in full; and (D) fourth, as a repayment of the Revolving Credit Loan, until
paid in full; provided that such repayment of
the Unit Acquisition Loan and/or NBB Revolving Credit Loan and/or Revolving
Credit Loan will not result in or require a corresponding reduction in the
Aggregate Unit Acquisition Commitment, Aggregate NBB Revolving Credit
Commitment or Aggregate Revolving Credit Commitment, respectively.”

(k)                                  Section
2.04 of the Credit Agreement is amended by
redesignating Section
2.04(e) “Prepayments;
Interest/Consequential Loss” as Section 2.04(f) and inserting a new Section 2.04(e) to
read in its entirety as follows:

 9
 

“(e)                            Mandatory Payments/Reductions of NBB
Revolving Credit Loans.  If (i) for any reason the Outstanding Amount
of all NBB Revolving Credit Loans at any time exceeds the Aggregate NBB
Revolving Credit Commitment then in effect, the Borrower shall immediately
prepay NBB Revolving Credit Loans in an aggregate amount equal to such excess
or (ii) at any time the amount of margin requirements for which NBB Revolving
Credit Loans were made are reduced, or entirely eliminated, the Borrower shall
immediately prepay NBB Revolving Credit Loans in an aggregate amount equal to
the excess of outstanding NBB Revolving Credit Loans over the margin
requirements then in effect.”

(l)                                     Section
2.05 of the Credit Agreement is amended by adding a
new Section 2.05(c) thereto to read in its entirety as follows:

“(c)                            NBB Revolving Credit Commitment. The Borrower may, upon notice to the
Administrative Agent, terminate the Aggregate NBB Revolving Credit Commitment
or permanently reduce the Aggregate NBB Revolving Credit Commitment prior to
the Maturity Date to an amount not less than the Outstanding Amount of the NBB
Revolving Credit Loans; provided that
(i) any such notice shall be received by the Administrative Agent not later
than 11:00 a.m., five Business Days prior to the date of termination or
reduction, and (ii) any such partial reduction shall be in an aggregate amount
of $1,000,000 or any whole multiple of $500,000 in excess thereof.   The Administrative Agent shall promptly
notify the Lenders having a NBB Revolving Credit Commitment of any such notice
of reduction or termination.  Once
reduced in accordance with this Section, the Aggregate NBB Revolving Credit
Commitment may not be increased, notwithstanding any contrary provision in Section 2.15.  Any reduction of the Aggregate NBB Revolving
Credit Commitment shall be applied to the NBB Revolving Credit Commitment of
each Lender having a NBB Revolving Credit Commitment according to its NBB Pro
Rata Share thereof.  The NBB Revolving
Credit Commitment Fee on the portion of the Aggregate NBB Revolving Credit Commitment
so terminated which has accrued to the effective date of any termination of the
Aggregate NBB Revolving Credit Commitment shall at Administrative Agent’s
option either be paid on the effective date of such termination or on the date
when such NBB Revolving Credit Commitment Fee would otherwise be due.”

(m)                               Section
2.06 of the Credit Agreement is deleted in its
entirety and the following is substituted therefor:

 “Section 2.06 
Repayment of Loans. The Borrower shall
repay to the Lenders on the Maturity Date the aggregate Outstanding Amount of
Revolving Credit Loans, NBB Revolving Credit Loans, if any, and Unit
Acquisition Loans outstanding on such date.”

(n)                                 Section
2.08 of the Credit Agreement is amended by adding a
new Section 2.08(d)
thereto to read in its entirety as follows:

“(d)                           NBB Revolving Credit Commitment Fee.  If
the Borrower requests and any one or more Lenders agrees to participate in, and
has been allocated a portion of the NBB Revolving Credit Commitment pursuant to
Section 2.15(d), then from and after
the NBB Revolving Credit Commitment Effective Date, the Borrower shall pay to
the Administrative Agent for the account of each Lender having a NBB Revolving
Credit Commitment, in accordance with its NBB Pro Rata Share of the Aggregate
NBB

 10

Revolving Credit Commitment, a commitment fee (“NBB
Revolving Credit Commitment Fee”) equal to the Applicable Rate
for NBB Revolving Credit Loans times the actual daily amount by which the
Aggregate NBB Revolving Credit Commitment (subject to reduction pursuant to Section 2.05(c)) exceeds the
Outstanding Amount of NBB Revolving Credit Loans.  The NBB Revolving Credit Commitment Fee shall
accrue at all times from the NBB Revolving Credit Commitment Effective Date
until the Maturity Date and shall be due and payable quarterly in arrears on
the last Business Day of each March, June, September and December, commencing
with the first such date to occur after the NBB Revolving Credit Commitment
Effective Date, and on the Maturity Date. 
The NBB Revolving Credit Commitment Fee shall be calculated quarterly in
arrears.  The NBB Revolving Credit
Commitment Fee shall accrue at all times, including at any time during which
one or more of the conditions in Article IV is not met.”

(o)                                 Section
2.11(a) of the Credit Agreement is amended by deleting
the third sentence thereof in its entirety and substituting the following
therefor:

“The
Administrative Agent will promptly distribute to each Lender its Pro Rata Share
(or in the case of a payment made in connection with NBB Revolving Credit
Loans, each Lender’s NBB Pro Rata Share) (or other applicable share as provided
herein) of such payment in like funds as received by wire transfer to such
Lender’s Lending Office.”

(p)                                 Section
2.11(d) of the Credit Agreement is deleted in its entirety
and the following is substituted therefor:

“(d)                           If at any time insufficient funds are
received by and available to the Administrative Agent to pay fully the
Obligations, or if a Default or Event of Default exists, any payment or
prepayment shall be applied in the following order: (i) to the payment of
enforcement expenses incurred by the Administrative Agent, including Attorney
Costs; (ii) to the ratable payment of all other fees, expenses, and indemnities
for which the Administrative Agent or Lenders have not been paid or reimbursed
in accordance with the Loan Documents (as used in this Section 2.11(d)(ii),
a “ratable payment”
for any Lender or the Administrative Agent shall be, on any date of
determination, that proportion which the portion of the total fees, expenses,
and indemnities owed to such Lender or the Administrative Agent bears to the
total aggregate fees and indemnities owed to all Lenders and the Administrative
Agent on such date of determination); (iii) to the ratable payment of accrued
and unpaid interest on the Outstanding Amount of Loans and the Outstanding
Amount of Obligations under Lender Hedging Agreements (it being understood that
for purposes of this clause (iii) the Outstanding Amount of Obligations under
Lender Hedging Agreements refers only to payments owing pursuant to Section
2(a) of the 2002 Master Agreement  form
promulgated by the ISDA (or equivalent type payment obligation if some other
form of Swap Contract is in effect)(as used in this Section 2.11(d)(iii),
“ratable payment”
means, for any Lender (or Lender Affiliate, in the case of Lender Hedging
Agreements), on any date of determination, that proportion which the accrued
and unpaid interest on the Outstanding Amount of Loans and the Outstanding
Amount of Obligations under Lender Hedging Agreements owed to such Lender (or
Lender Affiliate, in the case of Lender Hedging Agreements) bears to the total
accrued and unpaid interest on the Outstanding Amount of Loans and the
Outstanding Amount of Obligations under Lender Hedging Agreements owed to all
Lenders (and Affiliates, in the case of Lender Hedging Agreements)); (iv) to
the ratable payment of the Outstanding Amount of Loans and the

 11
 

Outstanding
Amount of Obligations under Lender Hedging Agreements (it being understood that
for purposes of this clause (iv) the Outstanding Amount of Obligations under
Lender Hedging Agreements refers to payments owing in connection with an Early
Termination Payment as defined in the 2002 Master Agreement form promulgated by
the ISDA (or equivalent type payment obligation if some other form of Swap
Contract is in effect)(as used in this Section 2.11(d)(iv), “ratable payment”
means for any Lender (or Lender Affiliate, in the case of Lender Hedging
Agreements), on any date of determination, that proportion which the
Outstanding Amount of Loans and the Outstanding Amount of Obligations under
Lender Hedging Agreements owed to such Lender (or Lender Affiliate, in the case
of Lender Hedging Agreements) bears to the Outstanding Amount of Loans owed to
all Lenders)(and Affiliates, in the case of Lender Hedging Agreements)); (v) to
Cash Collateralize the Letters of Credit; and (vi) to the payment of the
remaining Obligations, if any, in the order and manner the Required Lenders
deem appropriate.”

(q)                                 Section
2.14(c)(vi)of the Credit Agreement is deleted in its
entirety and the following is substituted therefor:

“A certificate of the Administrative Agent with respect to any amounts
owing under this clause (vi) shall be conclusive absent manifest error.”

(r)                                    Section
2.14(e)(v) of the Credit Agreement is deleted in its
entirety and the following is substituted therefor:

“The
Borrower shall promptly examine a copy of each Letter of Credit and each
amendment thereto and documents presented in connection with any drawing
thereunder that is delivered to it and, in the event of any claim of
noncompliance with the Borrower’s instructions or other irregularity, the
Borrower will immediately notify the L/C Issuer.”

(s)                                  Article II of the Credit Agreement is amended by adding
a new Section 2.15 thereto to read in
its entirety as follows:

“Section 2.15  Optional NBB Revolving Credit Commitment.

“(a)  Request for
Establishment of NBB Revolving Credit Commitment.  Provided no
Default or Event of Default has occurred and is continuing, that the Borrower
is in pro forma compliance with Section 7.15,
that the Collateral Coverage Ratio is at least 3.5 to 1.0 (giving pro forma
effect to any NBB Revolving Credit Borrowings actually requested), that the
Borrower has delivered to the Administrative Agent a pro forma NBB Borrowing
Certificate (reflecting what Swap Contracts are then in effect or will be in
effect upon the Borrower’s providing any required margin requirements, the
margin requirements under each such Swap Contract then in effect or proposed to
be entered into and the amount of the proposed NBB Credit Extension which would
be reflected on a NBB Borrowing Certificate delivered as of the end of the
month in which the NBB Credit Extension is requested) and that the Administrative
Agent consents thereto (which consent shall not be unreasonably withheld or
delayed), upon notice to the Administrative Agent (which shall promptly notify
the Lenders), the Borrower may request that a new revolving credit facility not
subject to Borrowing Base availability but subject to meeting a Collateral
Coverage Ratio of at least 3.5 to 1.0 (giving pro forma effect to any requested
NBB Credit Extension thereunder) be established in a total amount not exceeding

 12
 

$50,000,000 and which may be taken down in minimum increments of
$10,000,000 (the amount of each such take down comprising a separate tranche
under the NBB Revolving Credit Commitment); provided that
any NBB Credit Extension shall be used solely for the purpose of enabling the
Borrower to meet margin requirements under Swap Contracts; provided
further that any NBB Credit Extension shall be secured pari passu
with the Obligations.  At the time of
sending such request to establish the NBB Revolving Credit Commitment, the
Borrower (in consultation with the Administrative Agent) shall specify the time
period within which each Lender is requested to respond (which shall in no
event be less than 15 Business Days from the date of delivery of such notice to
the Lenders).

(b)                                 Lender Elections to Participate in NBB
Revolving Credit Commitment.  Each
Lender shall notify the Administrative Agent within such time period whether or
not it agrees to participate in the NBB Revolving Credit Commitment and, if so,
what percentage of the NBB Revolving Credit Commitment it is willing to commit
to fund.  Any Lender not responding
within such time period shall be deemed to have declined to participate in the
NBB Revolving Credit Commitment.  A
Lender that agrees to participate in the NBB Revolving Credit Commitment shall
have no obligation to participate in any subsequent requested increase in the
NBB Revolving Credit Commitment or to participate in the same percentage as it
participated in a prior NBB Revolving Credit Commitment.

(c)                                  Notification by Administrative Agent;
Additional Lenders.  The
Administrative Agent shall notify the Borrower and each Lender of the Lenders’
responses to the request made hereunder to participate in the NBB Revolving
Credit Commitment.  To achieve the full
amount of the requested NBB Revolving Credit Commitment (or any subsequent
increase in the amount of the NBB Revolving Credit Commitment) and subject to
the approval of the Administrative Agent (which approval shall not be
unreasonably withheld or delayed), the Borrower may also invite additional
Eligible Assignees to become Lenders pursuant to a joinder agreement in form
and substance satisfactory to the Administrative Agent and its counsel.  The Borrower shall have 30 calendar days from
the date the Administrative Agent notifies the Borrower of the Lenders’
responses to the request to participate in the NBB Revolving Credit Commitment
to invite additional Eligible Assignees and have them enter into a joinder
agreement.

(d)                                 Effective Date and Allocations.  If the NBB Revolving Credit Commitment
is established or increased in accordance with this Section, the Administrative
Agent and the Borrower shall determine the effective date (the “NBB Revolving Credit Commitment Effective Date”
and “NBB Revolving Credit Commitment Increase Effective
Date”, respectively) and the final allocation for such
established or increased NBB Revolving Credit Commitment.  The Administrative Agent shall promptly
notify the Borrower and the Lenders of the final allocation of such established
or increased NBB Revolving Credit Commitment and the NBB Revolving Credit
Commitment Effective Date or NBB Revolving Credit Commitment Increase Effective
Date, as applicable.

(e)                                  Conditions to Establishment/Increase of NBB
Revolving Credit Commitment.  As
a condition precedent to establishing or increasing the NBB Revolving Credit
Commitment, the Borrower shall deliver to the Administrative Agent a pro forma
NBB Borrowing Certificate and a certificate of each Loan Party dated as of the
NBB Revolving Credit Commitment Effective Date or NBB Revolving Credit
Commitment Increase Effective Date, as applicable (in sufficient copies for
each Lender) signed by a

 13
 

Responsible Officer of such Loan Party (i) certifying and attaching the
resolutions adopted by such Loan Party approving or consenting to the
establishment or increase of the NBB Revolving Credit Commitment, and (ii) in
the case of the Borrower, certifying that, before and after giving effect to
such establishment or increase, (A) the representations and warranties
contained in Article V and the other Loan
Documents are true and correct on and as of the NBB Revolving Credit Commitment
Effective Date or NBB Revolving Credit Commitment Increase Effective Date, as
the case may be, except to the extent that such representations and warranties
specifically refer to an earlier date, in which case they are true and correct
as of such earlier date, and except that for purposes of this Section 2.15, the
representations and warranties contained in Section
5.05(a) shall be deemed to refer to the most recent financial
statements furnished pursuant to clauses (a)
and (b), respectively, of Section 6.01, (B) no Default
exists, (C) pro forma compliance with Section 7.15,
and (D) that the Collateral Coverage Ratio is at least 3.5 to 1.0 giving pro
forma effect to any actually requested NBB Credit Extension.

(f)                                    NBB Revolving Credit Loans. 
Subject to and in reliance upon the terms, conditions, representations,
and warranties in the Loan Documents (including each NBB Borrowing
Certificate), each Lender that agrees to participate in the NBB Revolving
Credit Commitment (or in any increase thereof) severally, but not jointly,
agrees to make NBB Revolving Credit Loans to Borrower from time to time on any
Business Day during the period from the NBB Revolving Credit Commitment
Effective Date or NBB Revolving Credit Commitment Increase Effective Date, as
the case may be, to the Maturity Date, in an aggregate amount not to exceed at
any time outstanding the amount of such Lender’s NBB Pro Rata Share of one or
more NBB Revolving Credit Borrowings not to exceed, when aggregated with the
Outstanding Amount of NBB L/C Obligations, such Lender’s NBB Revolving Credit
Commitment.  NBB Revolving Credit
Borrowings may be repaid and reborrowed from time to time in accordance with
the terms and provisions of the Loan Documents; provided that, each such NBB Revolving Credit Borrowing must
occur on a Business Day and no later than the Business Day immediately
preceding the Maturity Date; and provided further that
at no time may the outstanding amount of NBB Revolving Credit Loans exceed the
actual required margin requirements under Swap Contracts then in effect.  No Lender shall be obligated to make any NBB
Revolving Credit Loan if the Outstanding Amount of all NBB L/C Obligations and
all NBB Revolving Credit Loans would exceed the Aggregate NBB Revolving Credit
Commitment.

(g)                                 Conflicting Provisions.  This Section shall supersede any
provisions in Sections 2.12 or 10.01 to the contrary.”

(t)                                    Article II of the Credit Agreement is amended by adding
a new Section 2.16 and a new Section 2.17 thereto
to read in their entirety as follows:

“2.16                 NBB Letters of Credit.

(a)                                  The NBB Letter of Credit Commitment.

(i)                                     Subject to the terms and conditions set forth
in Section 2.15, (A) the NBB L/C Issuer
agrees, in reliance upon the agreements of the other Lenders having a NBB
Revolving Credit Commitment set forth in this Section 2.16, (1) from time to time on
any Business Day during the period from the NBB Revolving Credit Commitment

 14
 

Effective Date until the NBB Letter of Credit Expiration Date, to issue
NBB Letters of Credit for the account of the Borrower or any Guarantor, and to
amend or renew NBB Letters of Credit previously issued by it, in accordance
with subsection (b) below, and (2) to honor drawings under the NBB Letters of
Credit; and (B) the Lenders having a NBB Revolving Credit Commitment severally
agree to participate in NBB Letters of Credit issued for the account of the
Borrower or any Guarantor; provided
that the NBB L/C Issuer shall not be obligated to make any NBB L/C Credit
Extension with respect to any NBB Letter of Credit, and no Lender having a NBB
Revolving Credit Commitment shall be obligated to participate in any NBB Letter
of Credit, if as of the date of such NBB L/C Credit Extension, (x) the
Outstanding Amount of all NBB L/C Obligations and all NBB Revolving Credit
Loans would exceed the Aggregate NBB Revolving Credit Commitment, or (y) the
aggregate Outstanding Amount of the NBB Revolving Credit Loans of any Lender
having a NBB Revolving Credit Commitment, plus
such Lender’s NBB Pro Rata Share of the Outstanding Amount of all NBB L/C
Obligations would exceed such Lender’s NBB Revolving Credit Commitment, or (z)
the Outstanding Amount of the NBB L/C Obligations would exceed the NBB Letter
of Credit Sublimit.  Within the foregoing
limits, and subject to the terms and conditions hereof, the Borrower’s ability
to obtain NBB Letters of Credit shall be fully revolving, and accordingly the
Borrower may, during the foregoing period, obtain NBB Letters of Credit to
replace NBB Letters of Credit that have expired or that have been drawn upon
and reimbursed.

(ii)                                  The NBB L/C Issuer shall be under no
obligation to issue any NBB Letter of Credit if:

(A)                              any order, judgment or decree of any Governmental Authority or
arbitrator shall by its terms purport to enjoin or restrain the NBB L/C Issuer
from issuing such NBB Letter of Credit, or any Law applicable to the NBB L/C
Issuer or any request or directive (whether or not having the force of law)
from any Governmental Authority with jurisdiction over the NBB L/C Issuer shall
prohibit, or request that the NBB L/C Issuer refrain from, the issuance of
letters of credit generally or such NBB Letter of Credit in particular or shall
impose upon the NBB L/C Issuer with respect to such NBB Letter of Credit any
restriction, reserve or capital requirement (for which the NBB L/C Issuer is
not otherwise compensated hereunder) not in effect on the Second Restatement
Date, or shall impose upon the NBB L/C Issuer any unreimbursed loss, cost or
expense which was not applicable on the Second Restatement Date and which the
NBB L/C Issuer in good faith deems material to it;

(B)                                subject to Section
2.16(b)(iii), the expiry date of such requested NBB Letter of
Credit would occur more than twelve months after the date of issuance or last
renewal, unless the Required NBB Revolving Credit Lenders have approved such
expiry date;

(C)                                the expiry date of such requested NBB Letter of Credit would occur
after the NBB Letter of Credit Expiration Date, unless all the Lenders having a
Revolving Credit Commitment have approved such expiry date;

(D)                               the issuance of such NBB Letter of Credit would violate one or more
policies of the NBB L/C Issuer generally applicable to all borrowers; or

 15
 

(E)                                 such NBB Letter of Credit is in a face amount
less than $500,000, or is to be used for a purpose other than as described in Section 6.14 or is
denominated in a currency other than Dollars.

(iii)                               The NBB L/C Issuer shall be under no obligation to amend any NBB Letter
of Credit if (A) the NBB L/C Issuer would have no obligation at such time to
issue such NBB Letter of Credit in its amended form under the terms hereof, or
(B) the beneficiary of such NBB Letter of Credit does not accept the proposed
amendment to such NBB Letter of Credit.

(b)                                 Procedures for Issuance and Amendment of NBB
Letters of Credit; NBB Evergreen Letters of Credit.

(i)                                     Each NBB Letter of Credit shall be issued or
amended, as the case may be, upon the request of the Borrower delivered to the
NBB L/C Issuer (with a copy to the Administrative Agent) in the form of a
Letter of Credit Application, appropriately completed and signed by a
Responsible Officer of the Borrower. 
Such Letter of Credit Application must be received by the NBB L/C Issuer
and the Administrative Agent not later than 11:00 a.m., New York time, at least
two Business Days (or such later date and time as the NBB L/C Issuer may agree
in a particular instance in its sole discretion) prior to the proposed issuance
date or date of amendment, as the case may be. 
In the case of a request for an initial issuance of a NBB Letter of
Credit, such Letter of Credit Application shall specify in form and detail
satisfactory to the NBB L/C Issuer: (A) the proposed issuance date of the
requested NBB Letter of Credit (which shall be a Business Day) and that such
letter of credit is to be issued under the NBB Revolving Credit Commitment; (B)
the amount thereof; (C) the expiry date thereof; (D) the name and address of
the beneficiary thereof; (E) the documents to be presented by such beneficiary
in case of any drawing thereunder; (F) the full text of any certificate to be
presented by such beneficiary in case of any drawing thereunder; and (G) such
other matters as the NBB L/C Issuer may require.  In the case of a request for an amendment of
any outstanding NBB Letter of Credit, such Letter of Credit Application shall
specify in form and detail satisfactory to the NBB L/C Issuer (A) the NBB Letter
of Credit to be amended; (B) the proposed date of amendment thereof (which
shall be a Business Day); (C) the nature of the proposed amendment; and (D)
such other matters as the NBB L/C Issuer may require.

(ii)                                  Promptly after receipt of any Letter of
Credit Application, the NBB L/C Issuer will confirm with the Administrative
Agent (by telephone or in writing) that the Administrative Agent has received a
copy of such Letter of Credit Application from the Borrower and, if not, the
NBB L/C Issuer will provide the Administrative Agent with a copy thereof.  Upon receipt by the NBB L/C Issuer of
confirmation from the Administrative Agent that the requested issuance or
amendment is permitted in accordance with the terms hereof, then, subject to
the terms and conditions hereof, the NBB L/C Issuer shall, on the requested
date, issue a NBB Letter of Credit for the account of the Borrower or enter
into the applicable amendment, as the case may be, in each case in accordance
with the NBB L/C Issuer’s usual and customary business practices.  Immediately upon the issuance of each NBB
Letter of Credit, each Lender having a NBB Revolving Credit Commitment for that
particular tranche of the NBB Revolving Credit Commitment pursuant to which
such NBB Letter of Credit is being issued shall be deemed to, and hereby
irrevocably and unconditionally agrees to, purchase from the NBB

 16
 

L/C Issuer a participation in such NBB Letter of Credit in an amount
equal to the product of such Lender’s participation percentage in that tranche
of the NBB Revolving Credit Commitment times
the amount of such NBB Letter of Credit.

(iii)                               If the Borrower so requests in any applicable Letter of Credit
Application, the NBB L/C Issuer may, in it sole and absolute discretion, agree
to issue a NBB Letter of Credit that has automatic renewal provisions (each, an
“NBB  Evergreen Letter of Credit”); provided that any such NBB Evergreen
Letter of Credit must permit the NBB L/C Issuer to prevent any such renewal at
least once in each twelve-month period (commencing with the date of
issuance of such NBB Letter of Credit) by giving prior notice to the
beneficiary thereof not later than a day (the “NBB
Nonrenewal Notice Date”)
in each such twelve-month period to be agreed upon at the time such NBB
Letter of Credit is issued.  Unless
otherwise directed by the NBB L/C Issuer, the Borrower shall not be required to
make a specific request to the NBB L/C Issuer for any such renewal.  Once an NBB Evergreen Letter of Credit has
been issued, the Lenders having a NBB Revolving Credit Commitment for the
tranche for which such NBB Evergreen Letter of Credit was issued shall be
deemed to have authorized (but may not require) the NBB L/C Issuer to permit
the renewal of such NBB Letter of Credit at any time to a date not later than
the NBB Letter of Credit Expiration Date; provided,
however, that the NBB L/C Issuer shall not permit any such renewal
if it has received notice on or before the 5th Business Day immediately preceding the NBB
Nonrenewal Notice Date (1) from the Administrative Agent that any of the
Lenders having a NBB Revolving Credit Commitment for the tranche for which such
NBB Evergreen Letter of Credit was issued has elected not to permit such
renewal or (2) from any Lender having a NBB Revolving Credit Commitment for the
tranche for which such NBB Evergreen Letter of Credit was issued stating that
one or more of the applicable conditions specified in Section 4.02 or Section 4.04 is not then satisfied
and directing the NBB L/C Issuer not to permit such renewal.  Notwithstanding anything to the contrary
contained herein, the NBB L/C Issuer shall have no obligation to permit the
renewal of any NBB Evergreen Letter of Credit at any time.

(iv)                              Promptly after its delivery of any NBB Letter of Credit or any
amendment to a NBB Letter of Credit to an advising bank with respect thereto or
to the beneficiary thereof, the NBB L/C Issuer will also deliver to the
Borrower and the Administrative Agent a true and complete copy of such NBB
Letter of Credit or amendment.

(c)                                  Drawings and Reimbursements; Funding of
Participations.

(i)                                     Upon any drawing under any NBB Letter of
Credit, the NBB L/C Issuer shall notify the Borrower and the Administrative
Agent thereof.   Not later than 11:00
a.m., New York time, on the date of any payment by the NBB L/C Issuer under a
NBB Letter of Credit (each such date, an “NBB  Honor Date”), the
Borrower shall reimburse the NBB L/C Issuer through the Administrative Agent in
an amount equal to the amount of such drawing. 
If the Borrower fails to so reimburse the NBB L/C Issuer by such time,
the Administrative Agent shall promptly notify each Lender having a NBB
Revolving Credit Commitment for the tranche for which such NBB  Letter of Credit was issued of the NBB Honor
Date, the amount of the unreimbursed drawing (the “NBB
Unreimbursed Amount”),
and such Lender’s participation in such NBB Letter of Credit (i.e., the amount
equal to the product of such Lender’s participation percentage in that tranche
of the NBB

 17
 

Revolving Credit Commitment pursuant to which such NBB Letter of Credit
was issued times the amount of
such NBB Letter of Credit).  In such
event, the Borrower shall be deemed to have requested a Borrowing of Base Rate
Loans under the NBB Revolving Credit Commitment for the tranche for which such
NBB Letter of Credit was issued to be disbursed on the NBB Honor Date in an
amount equal to the NBB Unreimbursed Amount, without regard to the minimum and
multiples specified in Section
2.03 for the principal amount of Base Rate Loans, but subject to
the amount of the unutilized portion of the Aggregate Revolving Credit
Commitment for the tranche for which such NBB Letter of Credit was issued and
the conditions set forth in Section 4.02 and Section 4.04
(other than the delivery of a NBB Borrowing Notice).  Any notice given by the NBB L/C Issuer or the
Administrative Agent pursuant to this Section 2.16(c)(i) may be given by telephone
if immediately confirmed in writing; provided
that the lack of such an immediate confirmation shall not affect the
conclusiveness or binding effect of such notice.

(ii)                                  Each Lender having a NBB Revolving Credit
Commitment for the tranche for which such NBB Letter of Credit was issued
(including the Lender acting as NBB L/C Issuer) shall upon any notice pursuant
to Section 2.16(c)(i)
make funds available to the Administrative Agent for the account of the NBB L/C
Issuer at the Administrative Agent’s Office in an amount equal to its
participation in such NBB Letter of Credit in an amount equal to the product of
such Lender’s participation percentage in that tranche of the NBB Revolving
Credit Commitment times the
amount of such NBB Unreimbursed Amount not later than 11:00 a.m., New York
time, on the Business Day specified in such notice by the Administrative Agent,
whereupon, subject to the provisions of Section 2.16(c)(iii), each Lender that so
makes funds available shall be deemed to have made a Base Rate Loan under the
NBB Revolving Credit Commitment for the related tranche to the Borrower in such
amount.  The Administrative Agent shall
remit the funds so received to the NBB L/C Issuer.

(iii)                               With respect to any NBB Unreimbursed Amount that is not fully
refinanced by a Borrowing of Base Rate Loans because the conditions set forth
in Section 4.02
or Section 4.04 cannot be satisfied or
for any other reason, the Borrower shall be deemed to have incurred from the
NBB L/C Issuer an NBB L/C Borrowing in the amount of the NBB Unreimbursed
Amount that is not so refinanced, which NBB L/C Borrowing shall be due and
payable on demand (together with interest) and shall bear interest at the Default
Rate.  In such event, each Lender’s
payment to the Administrative Agent for the account of the NBB L/C Issuer
pursuant to Section
2.16(c)(ii) shall be deemed payment in respect of its
participation in such NBB L/C Borrowing and shall constitute an NBB L/C Advance
from such Lender in satisfaction of its participation obligation under this Section 2.16.

(iv)                              Until each Lender having a NBB Revolving Credit Commitment for the
tranche for which a NBB Letter of Credit was issued funds its NBB Revolving
Credit Loan or NBB L/C Advance pursuant to this Section 2.16(c) to reimburse the NBB L/C
Issuer for any amount drawn under any NBB Letter of Credit, interest in respect
of such Lender’s proportionate share of such amount shall be solely for the
account of the NBB L/C Issuer.

(v)                                 The obligation of each Lender having a NBB
Revolving Credit Commitment to make NBB Revolving Credit Loans or NBB L/C
Advances to reimburse

 18
 

the NBB L/C Issuer for amounts drawn under NBB Letters of Credit, as
contemplated by this Section
2.16(c), shall be absolute and unconditional and shall not be
affected by any circumstance, including (A) any set-off, counterclaim,
recoupment, defense or other right which such Lender may have against the NBB
L/C Issuer, the Borrower or any other Person for any reason whatsoever, (B) the
occurrence or continuance of a Default or Event of Default, or (C) any other
occurrence, event or condition, whether or not similar to any of the
foregoing.  Any such reimbursement shall
not relieve or otherwise impair the obligation of the Borrower to reimburse the
NBB L/C Issuer for the amount of any payment made by the NBB L/C Issuer under
any NBB Letter of Credit, together with interest as provided herein.

(vi)                              If any Lender having a NBB Revolving Credit Commitment fails to make
available to the Administrative Agent for the account of the NBB L/C Issuer any
amount required to be paid by such Lender pursuant to the foregoing provisions
of this Section 2.16(c)
by the time specified in Section
2.16(c)(ii), the NBB L/C Issuer shall be entitled to recover
from such Lender (acting through the Administrative Agent), on demand, such
amount with interest thereon for the period from the date such payment is
required to the date on which such payment is immediately available to the NBB
L/C Issuer at a rate per annum equal to the Federal Funds Rate from time to
time in effect.  A certificate of the
Administrative Agent with respect to any amounts owing under this clause (vi)
shall be conclusive absent manifest error.

(d)                                 Repayment of Participations.

(i)                                     At any time after the NBB L/C Issuer has made
a payment under any NBB Letter of Credit and has received from any Lender such
Lender’s NBB L/C Advance in respect of such payment in accordance with Section 2.16(c), if
the Administrative Agent receives for the account of the NBB L/C Issuer any
payment related to such NBB Letter of Credit (whether directly from the
Borrower or otherwise, including proceeds of cash Collateral applied thereto by
the Administrative Agent), or any payment of interest thereon, the
Administrative Agent will distribute to such Lender an amount equal to the
product of such Lender’s participation percentage in that tranche of the NBB
Revolving Credit Commitment under which NBB Letter of Credit was issued times the amount of such payment) in the
same funds as those received by the Administrative Agent.

(ii)                                  If any payment received by the Administrative
Agent for the account of the NBB L/C Issuer pursuant to Section 2.16(c)(i) is
required to be returned, each Lender having a NBB Revolving Credit Commitment
for the related tranche shall pay to the Administrative Agent for the account
of the NBB L/C Issuer an amount equal to the product of such Lender’s
participation percentage in that tranche of the NBB Revolving Credit Commitment
times the amount of such required
returned payment on demand of the Administrative Agent, plus interest thereon
from the date of such demand to the date such amount is returned by such
Lender, at a rate per annum equal to the Federal Funds Rate from time to time
in effect.

(e)                                  Obligations Absolute.  The
obligation of the Borrower to reimburse the NBB L/C Issuer for each drawing
under each NBB Letter of Credit, and to repay each NBB L/C Borrowing and each
drawing under a NBB Letter of Credit that is refinanced by a Borrowing of NBB
Revolving Credit Loans, shall be absolute, unconditional and

 19
 

irrevocable, and shall be paid strictly in accordance with the terms of
this Agreement under all circumstances, including the following:

(i)                                     any lack of validity or enforceability of
such NBB Letter of Credit, this Agreement, or any other agreement or instrument
relating thereto;

(ii)                                  the existence of any claim, counterclaim, set-off,
defense or other right that the Borrower may have at any time against any
beneficiary or any transferee of such NBB Letter of Credit (or any Person for
whom any such beneficiary or any such transferee may be acting), the NBB L/C
Issuer or any other Person, whether in connection with this Agreement, the
transactions contemplated hereby or by such NBB Letter of Credit or any
agreement or instrument relating thereto, or any unrelated transaction;

(iii)                               any draft, demand, certificate or other document presented under such
NBB Letter of Credit proving to be forged, fraudulent, invalid or insufficient
in any respect or any statement therein being untrue or inaccurate in any
respect; or any loss or delay in the transmission or otherwise of any document
required in order to make a drawing under such NBB Letter of Credit;

(iv)                              any payment by the NBB L/C Issuer under such NBB Letter of Credit
against presentation of a draft or certificate that does not strictly comply
with the terms of such NBB Letter of Credit; or any payment made by the NBB L/C
Issuer under such NBB Letter of Credit to any Person purporting to be a trustee
in bankruptcy, debtor-in-possession, assignee for the benefit of
creditors, liquidator, receiver or other representative of or successor to any
beneficiary or any transferee of such NBB Letter of Credit, including any
arising in connection with any proceeding under any Debtor Relief Law; or

(v)                                 any other circumstance or happening
whatsoever, whether or not similar to any of the foregoing, that might
otherwise constitute a defense available to, or a discharge of, the Borrower.

The
Borrower shall promptly examine a copy of each NBB Letter of Credit and each
amendment thereto and documents presented in connection with any drawing
thereunder that is delivered to it and, in the event of any claim of
noncompliance with the Borrower’s instructions or other irregularity, the
Borrower will immediately notify the NBB L/C Issuer.  The Borrower shall be conclusively deemed to
have waived any such claim against the NBB L/C Issuer and its correspondents unless
such notice is given as aforesaid.

(f)                                    Role of L/C Issuer.  Each
Lender having a NBB Revolving Credit Commitment and the Borrower agree that, in
paying any drawing under a NBB Letter of Credit, the NBB L/C Issuer shall not
have any responsibility to obtain any document (other than any sight draft,
certificates and documents expressly required by the NBB Letter of Credit) or
to ascertain or inquire as to the validity or accuracy of any such document or
the authority of the Person executing or delivering any such document.  No Agent-Related Person nor any of the
respective correspondents, participants or assignees of the NBB L/C Issuer
shall be liable to any Lender for (i) any action taken or omitted in connection
herewith at the request or with the approval of the Lenders or the Required

 20

NBB Revolving Credit Lenders, as applicable, (ii) any action taken or
omitted in the absence of gross negligence or willful misconduct; or (iii) the
due execution, effectiveness, validity or enforceability of any document or
instrument related to any NBB Letter of Credit or Letter of Credit
Application.  The Borrower hereby assumes
all risks of the acts or omissions of any beneficiary or transferee with
respect to its use of any NBB Letter of Credit; provided, however, that this assumption is not intended to,
and shall not, preclude the Borrower’s pursuing such rights and remedies as it
may have against the beneficiary or transferee at law or under any other
agreement.  No Agent-Related
Person, nor any of the respective correspondents, participants or assignees of
the NBB L/C Issuer, shall be liable or responsible for any of the matters
described in clauses (i) through (v) of Section 2.16(e); provided, however, that anything in such clauses to the
contrary notwithstanding, the Borrower may have a claim against the NBB L/C
Issuer, and the NBB L/C Issuer may be liable to the Borrower, to the extent,
but only to the extent, of any direct, as opposed to consequential or
exemplary, damages suffered by the Borrower which the Borrower proves were
caused by the NBB L/C Issuer’s willful misconduct or gross negligence or the
NBB L/C Issuer’s willful failure to pay under any NBB Letter of Credit after
the presentation to it by the beneficiary of a drawing strictly complying with
the terms and conditions of a NBB Letter of Credit.  In furtherance and not in limitation of the
foregoing, the NBB L/C Issuer may accept documents that appear on their face to
be in order, without responsibility for further investigation, regardless of
any notice or information to the contrary, and the NBB L/C Issuer shall not be
responsible for the validity or sufficiency of any instrument transferring or
assigning or purporting to transfer or assign a NBB Letter of Credit or the
rights or benefits thereunder or proceeds thereof, in whole or in part, which
may prove to be invalid or ineffective for any reason.

(g)                                 Cash Collateral.  
Upon the request of the Administrative Agent, (i) if the NBB L/C Issuer
has honored any full or partial drawing request under any NBB Letter of Credit
and such drawing has resulted in a NBB L/C Borrowing, or (ii) if, as of the NBB
Letter of Credit Expiration Date, any NBB Letter of Credit may for any reason
remain outstanding and partially or wholly undrawn, or (iii) if at any time the
Collateral Coverage Ratio is less than 3.5 to 1.0, the Borrower shall
immediately Cash Collateralize the then Outstanding Amount of all NBB L/C
Obligations (in an amount equal to such Outstanding Amount).  The Borrower hereby grants the Administrative
Agent, for the benefit of the NBB L/C Issuer and the Lenders having a NBB
Revolving Credit Commitment, a Lien on all such cash and deposit accounts at
any Lender having a NBB Revolving Credit Commitment.

(h)                                 Applicability of ISP98. 
Unless otherwise expressly agreed by the NBB L/C Issuer and the Borrower
when a NBB Letter of Credit is issued, the rules of the “International Standby
Practices 1998” published by the Institute of International Banking Law &
Practice (or such later version thereof as may be in effect at the time of
issuance) shall apply to each NBB Letter of Credit.

(i)                                     NBB Letter of Credit Fees.  The
Borrower shall pay to the Administrative Agent for the account of each Lender
having a NBB Revolving Credit Commitment for a tranche for which a NBB  Letter of Credit was issued a NBB Letter of
Credit fee for each NBB Letter of Credit issued under such tranche equal to the
Applicable Rate times the actual daily undrawn amount under each NBB Letter of
Credit issued under such tranche, with each such Lender receiving an amount
equal to the

 21
 

product of such Lender’s participation
percentage in that tranche of the NBB Revolving Credit Commitment under which
such NBB Letter of Credit was issued times the applicable NBB Letter of Credit
fee.  Such fee for each NBB Letter of
Credit shall be due and payable on the last Business Day of each March, June,
September and December, commencing with the first such date to occur after the
issuance of such NBB Letter of Credit, and on the NBB Letter of Credit
Expiration Date.  If there is any change
in the Applicable Rate during any quarter, the actual daily undrawn amount of
each NBB Letter of Credit shall be computed and multiplied by the Applicable
Rate separately for each period during such quarter that such Applicable Rate
was in effect.

(j)                                     Fronting Fee and Documentary and Processing
Charges Payable to NBB L/C Issuer.  The Borrower shall pay
directly to the NBB L/C Issuer for its own account a fronting fee in an amount
with respect to each NBB Letter of Credit issued equal to the greater of (i)
$500 and (ii) 1⁄4 of 1% calculated on the face amount thereof.   In addition, the Borrower shall pay directly
to the NBB L/C Issuer for its own account the customary issuance, presentation,
amendment and other processing fees, and other standard costs and charges, of
the NBB L/C Issuer relating to letters of credit as from time to time in
effect.  Such fees and charges are due
and payable on demand and are nonrefundable.

(k)                                  Conflict with Letter of Credit Application.  In
the event of any conflict between the terms hereof and the terms of any Letter
of Credit Application, the terms hereof shall control.

2.17                        Pari Passu Lien Securing
Lender Hedging Agreements.  All Obligations arising under the Loan
Documents, including, without limitation, Obligations under this Agreement and
Obligations under any Lender Hedging Agreement (but not Indebtedness of the
Borrower or any MarkWest Inc. Subsidiary owing to any non-Lender or non-Lender
Affiliate in connection with any Swap Contract), shall be secured  pari passu
by the Collateral.”

(u)                                 Section 4.02 of the Credit Agreement is
deleted and the following is substituted therefor:

“4.02                 Conditions to all Loans each L/C Credit Extension and
NBB L/C Credit Extension.  The obligation of each Lender to honor any
Borrowing Notice and the obligation of the L/C Issuer to issue any Letter of
Credit and the obligation of the NBB L/C Issuer to issue any NBB Letter of
Credit is subject to the following conditions precedent:

(a)                                  The representations and warranties of the
Loan Parties contained in Article
V, or which are contained in any document furnished at any time
under or in connection herewith, including, but not limited to the Collateral
Documents, shall be true and correct in all material respects on and as of the
date of such Loan is made, continued or converted, as applicable, or such
Letter of Credit or NBB Letter of Credit is issued except to the extent that
such representations and warranties specifically refer to an earlier date, in
which case they shall be true and correct as of such earlier date.

(b)                                 Since the date of the last delivered
financial statements, there has been no event or circumstance that has or could
reasonably be expected to have a Material Adverse Effect.

 22
 

(c)                                  No Default or Event of Default shall exist or
would result from such proposed Loan, continuation or conversion, L/C Credit
Extension or NBB L/C Credit Extension.

(d)                                 The Administrative Agent and, if applicable,
the L/C Issuer, and, if applicable the NBB L/C Issuer shall have received a
Request for Credit Extension and, if applicable, a Letter of Credit Application
in accordance with the requirements hereof.

(e)                                  The Administrative Agent shall have received,
in form and substance reasonably satisfactory to it, such other assurances,
certificates, documents or consents related to the foregoing as the
Administrative Agent reasonably may require.

(f)                                    The Borrower shall have delivered to the
Administrative Agent Federal Reserve Form U-1 provided for in the Margin
Regulations, which shall contain statements that, in the judgment of the
Administrative Agent, permit the transactions contemplated hereby to be made in
accordance with the Margin Regulations.

Each
Request for Credit Extension submitted by the Borrower shall be deemed to be a
representation and warranty that the conditions specified in Sections 4.02(a), (b) and (c) have been
satisfied on and as of the date of the applicable Credit Extension.”

(v)                                 Article IV of the Credit Agreement is amended by adding
a new Section 4.04 thereto to read in
its entirety as follows:

“4.04                  Conditions to all NBB
Revolving Credit Loans and NBB L/C Credit Extensions.  The
obligation of each Lender having a NBB Revolving Credit Commitment to fund its
portion of any NBB Revolving Credit Loan and the obligation of the NBB L/C
Issuer to issue any NBB Letter of Credit shall be subject to the additional
condition precedent that the Borrower confirm in writing that after giving pro
forma effect to the requested NBB Credit Extension, the Collateral Coverage
Ratio is at least 3.5 to 1.0.”

(w)                               Section
5.06 of the Credit Agreement Litigation is amended by deleting the
words “the Any” and substituting therefor the word “any”.

(x)                                   The introductory clause to the first sentence
of Article VI of the Credit Agreement Affirmative Covenants is deleted and the following
is substituted therefor:

“So long as any Lender shall have any Commitment hereunder, or any Loan
or other Obligation shall remain unpaid or unsatisfied, or any Letter of Credit
or NBB Letter of Credit shall remain outstanding, each Loan Party shall:”

(y)                                 Section
6.02 of the Credit Agreement is amended by
redesignating Section
6.02(g) as Section
6.02(h), deleting the word “and” at the end of Section 6.02(f)
and inserting a new Section
6.02(g) to read in its entirety as follows:

“(g)                           within twenty (20) calendar days after the
end of each calendar month commencing with the calendar month following the NBB
Revolving Credit Commitment Effective Date and thereafter for each month during
which any NBB Revolving Credit Loans are outstanding, (i) a completed NBB
Borrowing Certificate certifying as of the last day of such calendar month the
then existing Swap Contracts and the margin

 23
 

requirements thereunder, certified as complete and correct and signed
on behalf of the Borrower by its chief financial officer or treasurer, and (ii)
such supporting documentation as the Administrative Agent shall request; and”

(z)                                   Section
6.12 of the Credit Agreement is amended by deleting
the word “and” at the end of clause (A) and inserting after the word “partners”
at the end of such Section the following:

“and
(C) the NBB Revolving Credit Facility solely to enable the Borrower to meet
margin requirements under Swap Contracts.”

(aa)                            Section
6.15 of the Credit Agreement is amended by (i)
deleting from the first sentence of such Section the words “the substantially
in the form and upon the terms of Exhibit E” and substituting therefor the
words “form and substance satisfactory to the Administrative Agent” and (ii)
deleting from the second sentence of such Section the words “substantially in
the form and upon the terms of Exhibit E” and substituting therefor the words “in
form and substance satisfactory to the Administrative Agent”.

(bb)                          The introductory clause to the first sentence
of Article VII of the Credit Agreement Negative Covenants is deleted and the
following is substituted therefor:

“So long as any Lender shall have any Commitment hereunder, or any Loan
or other Obligations shall remain unpaid or unsatisfied, or any Letter of
Credit or NBB Letter of Credit shall remain outstanding, the Borrower agrees
that it shall not, nor shall it permit any Loan Party to, directly or
indirectly:”

(cc)                            Section
7.01(n) of the Credit Agreement is deleted in its
entirety and the following is substituted therefor:

“(n)                           Liens incurred in the ordinary course of
business in connection with margin requirements under Swap Contracts where a
non-Lender or non-Lender Affiliate is a counterparty; provided
such margin requirements are met solely with any combination of (i) cash drawn
under the NBB Revolving Credit Facility or (ii) available cash of the Borrower
not representing monies received in connection with any Revolving Credit
Borrowing or Unit Acquisition Borrowing.”

(m)                               Section
7.13 of the Credit Agreement is deleted in its
entirety and the following is substituted therefor:

 “Section 7.13 
Use of Proceeds. Use the proceeds of
any Loan or Letter of Credit or NBB Letter of Credit for purposes other than
those permitted by Section
6.12.”

(dd)                          Section
10.01(a)(v) of the Credit Agreement is deleted and the
following is substituted therefor:

“(v)                           change the Pro Rata Share of any Lender
except for reductions in a Lender’s Pro Rata Share resulting from an increase
in the Aggregate Revolving Credit Commitment pursuant to Section
2.13 and such Lender’s failure to wholly or proportionately
participate in such increase or change the NBB Pro Rata Share of any Lender
having a NBB Revolving Credit Commitment except for reductions in a Lender’s
NBB Pro Rata Share resulting from an increase in the Aggregate NBB Revolving
Credit Commitment

 24
 

pursuant to Section 2.15 and such Lender’s
failure to wholly or proportionately participate in such increase;”

(ee)                            Section
10.01(a) of the Credit Agreement is amended by deleting
the last sentence of such Section and substituting therefor the following:

“Notwithstanding
anything to the contrary herein, any Lender that has failed to fund any portion
of the Loans or participation in L/C Obligations required to be funded by it
hereunder shall not have any right to approve or disapprove any amendment,
waiver or consent hereunder, except that the Pro Rata Share of such Lender (or
the NBB Pro Rata Share of any Lender having a NBB Revolving Credit Commitment)
may not be increased without the consent of such Lender.”

(ff)                                Section
10.01 of the Credit Agreement is amended by adding
thereto a new clause (e) to read in its entirety as follows:

“(e)                            Notwithstanding any provision herein to the
contrary, if the Commitments have been terminated, and the only outstanding
Obligations are amounts owed pursuant to one or more Lender Hedging Agreements,
the Administrative Agent will, and is hereby authorized to, (A) release the
Liens created under the Loan Documents and (B) release all Guaranties of the
Borrower; provided, that
contemporaneously with such release, (i) the Borrower (and, if applicable, the
Subsidiary that is a party to such Lender Hedging Agreements) (A) executes a
margin agreement in form and substance acceptable to such Lender(s) (or its
Affiliates) that are parties to such Lender Hedging Agreements (the “Lender Counterparties”)
and (B), if required, provides collateral in the form of cash or a letter of
credit having an aggregate value acceptable to such Lender Counterparties, and
(ii) if such Lender Hedging Agreement is executed by a Subsidiary of the
Borrower (other than Excluded MLP Entities) and the Borrower is not a party
thereto, the Borrower executes a guaranty covering such Subsidiary’s
obligations thereunder, such guaranty to be in form and substance satisfactory
to the Lender Counterparties.  Any
release under this Section
10.01(e) must be in writing and signed by the Administrative
Agent.”

(gg)                          Schedule
2.01 of the Credit Agreement is deleted and  Schedule 2.01 attached to this Amendment is
substituted therefor.

(hh)                          Exhibit
A-1 Form of Borrowing Notice  and Exhibit A-2 Form
of Conversion/Continuation Notice  of
the Credit Agreement are deleted and Exhibit A-1  Form
of Borrowing Notice and Exhibit A-2  Form
of Conversion/Continuation Notice attached to this Amendment are
substituted therefor.

(ii)                                  The Credit Agreement is amended by adding
thereto a new Exhibit B-3  Form of NBB Revolving Credit Note  in the
form attached to this Amendment as Exhibit B-3.

(jj)                                  Exhibit
C-1 Form of Compliance Certificate  and Exhibit C-2 Form of Borrowing Base Report of the
Credit Agreement are deleted and Exhibit C-1  Form
of Compliance Certificate and Exhibit C-2  Form
of Borrowing Base Report attached to this Amendment are substituted
therefor.

(kk)                            The Credit Agreement is amended by adding
thereto a new Exhibit F  Form of NBB Borrowing Certificate  in the
form attached to this Amendment as Exhibit F.

 25
 

Paragraph 2.                       Effective
Date. This Amendment
shall not become effective until the date (such date, the “First Amendment Effective Date”)
the Administrative Agent receives all of the agreements, documents,
certificates, instruments, and other items described below:

(a)                                  this Amendment, executed by the Borrower, the
Guarantors, and each other Lender and the L/C Issuer;

(b)                                 from the Borrower and the existing Guarantors,
such certificates of secretary, assistant secretary, manager, or general
partner, as applicable, as the Administrative Agent may require, certifying (i)
resolutions of its board of directors, managers or members (or their
equivalent) authorizing the execution and performance of this Amendment and the
other Loan Documents which such Person is executing in connection herewith,
(ii) the incumbency and signature of the officer executing such documents, and
(iii) no change in such Person’s organizational documents since August 18,
2006;

(c)                                  an amendment fee equal to 25 basis points of
the sum of the Aggregate Revolving Credit Commitment ($40,000,000) and the
Aggregate Unit Acquisition Commitment ($15,000,000) has been paid to the
Administrative Agent to be shared proportionately by all the Lenders approving
this Amendment on or before February 16, 2007;

(d)                                 fees and expenses required to be paid
pursuant to Paragraph 5
of this Amendment, to the extent invoiced prior to the First Amendment
Effective Date; and

(e)                                  such other assurances, certificates,
documents and consents as the Administrative Agent may require.

Paragraph 3.                       Acknowledgment
and Ratification. As
a material inducement to the Administrative Agent and the Lenders to execute
and deliver this Amendment, each of the Borrower and the Guarantors (i)
consents to the agreements in this Amendment, (ii) agrees and acknowledges that
the execution, delivery, and performance of this Amendment shall in no way
release, diminish, impair, reduce, or otherwise affect the respective
obligations of the Borrower or any Guarantor under the Loan Documents to which
it is a party, which Loan Documents shall remain in full force and effect, and
all rights thereunder are hereby ratified and confirmed.  The Administrative Agent and each Lender
acknowledge that pursuant to a Limited Waiver dated December 20, 2006, (i)
MarkWest Michigan, Inc. and MarkWest Resources, Inc. have merged with and into
the Borrower and (ii) Matrex LLC is no longer a Guarantor, having become a
subsidiary of Basin Pipeline, LLC, which is an Excluded MLP Entity.

Paragraph 4.                     Representations. As a material inducement to the
Administrative Agent and the Lenders to execute and deliver this Amendment,
each of the Borrower and the Guarantors represents and warrants to the
Administrative Agent and the Lenders that as of the First Amendment Effective
Date and as of the date of execution of this Amendment, (a) all representations
and warranties in the Loan Documents are true and correct in all material
respects as though made on the date hereof, except to the extent that any of
them speak to a different specific date, and (b) no Default or Event of Default
exists.

Paragraph 5.                     Expenses,
Funding Losses.  The Borrower shall pay on demand all
reasonable costs, fees, and expenses paid or incurred by the Administrative
Agent incident to this Amendment, including, without limitation, Attorney Costs
in connection with the negotiation, preparation, delivery, and execution of
this Amendment and any related documents, filing and recording costs, and the
costs of title insurance endorsements.

 26
 

Paragraph 6.                       Miscellaneous. This Amendment is a “Loan Document”
referred to in the Credit Agreement.  The
provisions relating to Loan Documents in Article X of the Credit Agreement are incorporated
in this Amendment by reference.  Unless
stated otherwise (a) the singular number includes the plural and vice versa and
words of any gender include each other gender, in each case, as appropriate,
(b) headings and captions may not be construed in interpreting provisions, (c)
this Amendment must be construed, and its performance enforced, under Texas law
and applicable  federal law, (d) if any
part of this Amendment is for any reason found to be unenforceable, all other
portions of it nevertheless remain enforceable, and (e) this Amendment may be
executed in any number of counterparts with the same effect as if all
signatories had signed the same document, and all of those counterparts must be
construed together to constitute the same document.

Paragraph 7.                       ENTIRE AGREEMENT.
THIS AMENDMENT REPRESENTS THE FINAL AGREEMENT BETWEEN THE PARTIES ABOUT THE
SUBJECT MATTER OF THIS AMENDMENT AND MAY NOT BE CONTRADICTED BY EVIDENCE OF
PRIOR, CONTEMPORANEOUS, OR SUBSEQUENT ORAL AGREEMENTS OF THE PARTIES. THERE ARE
NO UNWRITTEN ORAL AGREEMENTS BETWEEN THE PARTIES.

Paragraph 8.                       Parties. This Amendment binds and inures to the
benefit of the Borrower, the Guarantors, the Administrative Agent, the L/C
Issuer, the other Lenders, and their respective successors and assigns.

Paragraph 9.                     Further
Assurances. The
parties hereto each agree to execute from time to time such further documents
as may be necessary to implement the terms of this Agreement.

The parties hereto have
executed this Amendment in multiple counterparts to be effective as of the
Effective Date.

 27

IN WITNESS WHEREOF, the
parties hereto have caused this Agreement to be duly executed as of the date
first above written.

	
  

  	
  MARKWEST HYDROCARBON, INC.,

  
	
   

  	
  a Delaware corporation, as Borrower

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  	
  /s/ ANDREW L. SCHROEDER

  	
   

  
	
   

  	
   

  	
  Andrew L. Schroeder

  
	
   

  	
   

  	
  Vice President, Treasurer and Secretary

  

 

 1
 

 

	
  

  	
  MARKWEST ENERGY GP, L.L.C.,

  
	
   

  	
  a Delaware corporation, as a Guarantor

  
	
   

  	
   

  
	
   

  	
  By: 

  	
   

  	
  /s/ ANDREW L. SCHROEDER

  	
   

  
	
   

  	
   

  	
  Andrew L. Schroeder

  
	
   

  	
   

  	
  Vice President and Treasurer

  

 

 2
 

 

	
  

  	
  ROYAL BANK OF CANADA,

  
	
   

  	
  as Administrative Agent and Collateral Agent

  
	
   

  	
   

  
	
   

  	
  By: 

  	
   

  	
  /s/ ANN HURLEY

  	
   

  
	
   

  	
  Name:

  	
  Ann Hurley

  
	
   

  	
  Title:

  	
  Manager, Agency

  

 

 3
 

 

	
  

  	
  ROYAL BANK OF CANADA, as a
  Lender

  
	
   

  	
  and L/C Issuer

  
	
   

  	
   

  
	
   

  	
  By: 

  	
   

  	
  /s/ JASON S. YORK

  	
   

  
	
   

  	
  Name:

  	
  Jason S. York

  
	
   

  	
  Title:

  	
  Authorized Signatory

  
						

 

 4
 

 

	
  

  	
  SUNTRUST BANK,

  
	
   

  	
  as a Lender

  
	
   

  	
   

  
	
   

  	
  By: 

  	
   

  	
  /s/ JOSEPH M. MCCREERY

  	
   

  
	
   

  	
  Name:

  	
  Joseph M. McCreery

  
	
   

  	
  Title:

  	
  Director

  
						

 

 5
 

 

	
  

  	
  US BANK NATIONAL ASSOCIATION,

  
	
   

  	
  as a Lender

  
	
   

  	
   

  
	
   

  	
  By: 

  	
   

  	
  /s/ JUSTIN M. ALEXANDER

  	
   

  
	
   

  	
  Name:

  	
  Justin M. Alexander

  
	
   

  	
  Title:

  	
  Vice President

  
						

 

 6
 

 

	
  

  	
  BANK OF OKLAHOMA, N.A.

  
	
   

  	
  as a Lender

  
	
   

  	
   

  
	
   

  	
  By: 

  	
   

  	
  /s/ MONCIA M. MORTON

  	
   

  
	
   

  	
  Name:

  	
  Monica M. Morton

  
	
   

  	
  Title:

  	
  Commercial Banking Officer

  
						

 

 7

SCHEDULE 2.01

COMMITMENTS

	
  Lender

  	
   

  	
  Revolving

  Credit

  Commitments

  	
   

  	
  Unit Acquisition

  Commitments

  	
   

  	
  NBB

  Revolving

  Credit

  Commitments

  	
   

  	
  Total Commitment

  	
   

  
	
  Royal Bank of Canada

  	
   

  	
  $

  	
  14,545,454.55

  	
   

  	
  $

  	
  5,454,545.45

  	
   

  	
  $

  	
  0.00

  	
   

  	
  $

  	
  20,000,000.00

  	
   

  
	
  SunTrust Bank

  	
   

  	
  $

  	
  10,909,090.91

  	
   

  	
  $

  	
  4,090,909.09

  	
   

  	
  $

  	
  0.00

  	
   

  	
  $

  	
  15,000,000.00

  	
   

  
	
  U.S. Bank National
  Association

  	
   

  	
  $

  	
  7,272,727.27

  	
   

  	
  $

  	
  2,727,272.73

  	
   

  	
  $

  	
  0.00

  	
   

  	
  $

  	
  10,000,000.00

  	
   

  
	
  Bank of Oklahoma, N.A.

  	
   

  	
  $

  	
  7,272,727.27

  	
   

  	
  $

  	
  2,727,272.73

  	
   

  	
  $

  	
  0.00

  	
   

  	
  $

  	
  10,000,000.00

  	
   

  
	
  Total Commitment:

  	
   

  	
  $

  	
  40,000,000.00

  	
   

  	
  $

  	
  15,000,000.00

  	
   

  	
  $

  	
  0.00

  	
   

  	
  55,000,000.00

  	
   

  

 

EXHIBIT
A-1

FORM OF
BORROWING NOTICE

Date:                   ,          

To:                              Royal Bank of Canada, as Administrative Agent

Ladies and Gentlemen:

Reference is made to that
certain Second Amended and Restated Credit Agreement, dated as of August 18,
2006 (as amended, restated, extended, supplemented or otherwise modified in
writing from time to time, the “Agreement;”  the
terms defined therein being used herein as therein defined), among MarkWest
Hydrocarbon, Inc., a Delaware corporation (the “Borrower”), Royal Bank of Canada, as
Administrative Agent, and the Lenders from time to time party thereto.

The undersigned hereby
requests a revolving loan:

I.                                         REVOLVING CREDIT FACILITY

1.                                       Status Information for the Revolving Credit
Facility

(a)                                  Amount of Aggregate Revolving Credit
Commitment: $40,000,000 (prior to Revolving
Credit Commitment Increase Effective Date) OR $               (after
Revolving Credit Commitment Increase Effective Date)

(b)                                 Revolving Credit Loans outstanding prior to
the Revolving Credit Borrowing requested herein: $               

(c)                                  Letters of Credit outstanding prior to the
Revolving Credit Borrowing requested herein: 
$               

(d)                                 Principal amount of Revolving Credit Loans
available to be borrowed (1(a) minus the sum of 1(b) and 1(c)): $               

2.                                       Amount of Revolving Credit Borrowing: $               

3(a).                         Initial Borrowing Base as of June 30, 2006: $               
OR

3(b).                        Borrowing Base as of most recent calendar
month end: $               

4.                                       Requested date of Revolving Credit Borrowing:
                           ,
200  .

5.                                       Requested Type of Loan for Revolving Credit
Borrowing and applicable Dollar
amount:

(a)                                  Base Rate Loan for $               

(b)                                 Eurodollar Rate Loan with Interest Period of:

	
  

  	
  (i)

  	
  one month for

  	
  $                     

  
	
   

  	
  (ii)

  	
  two months for

  	
  $                     

  

 

 1
 

 

	
  

  	
  (iii)

  	
  three months for

  	
  $                     

  
	
   

  	
  (iv)

  	
  six months for

  	
  $                     

  

 

6.                                       Purpose of Revolving Credit Loan:

o  Finance accounts receivable
and/or inventory

o  To
pay fees, costs and expenses owed pursuant to the Agreement

o  Finance purchase of MLP Units (in
an amount not to exceed the increase in the Aggregate Revolving Credit
Commitment after the Revolving Credit Commitment Increase Effective Date)

II.                                     UNIT ACQUISITION FACILITY

1.                                       Status Information for the Unit Acquisition
Facility

(a)                                  Amount of Aggregate Unit Acquisition
Commitment: $15,000,000

(b)                                 Unit Acquisition Loans outstanding prior to
the Unit Acquisition Borrowing requested herein: $                     

(c)                                  Principal amount of Unit Acquisition Loans
available to be borrowed (1(a) minus 1(b)): $                     

2.                                       Amount of Unit Acquisition Borrowing: $                     

3                                          Requested date of Unit Acquisition Borrowing:
                               ,
200  .

4.                                       Requested Type of Loan for Unit Acquisition
Borrowing and applicable Dollar
amount:

(a)                                  Base Rate Loan for $                     

(b)                                 Eurodollar Rate Loan with Interest Period of:

	
  

  	
  (i)

  	
  one month for

  	
  $                     

  
	
   

  	
  (ii)

  	
  two months for

  	
  $                     

  
	
   

  	
  (iii)

  	
  three months for

  	
  $                     

  
	
   

  	
  (iv)

  	
  six months for

  	
  $                     

  

 

III.                                 NBB REVOLVING CREDIT FACILITY

1.                                       Status Information for the NBB Revolving
Credit Facility

(a)                                  Amount of Aggregate NBB Revolving Credit
Commitment: $0.00

(b)                                 NBB Revolving Credit Loans outstanding prior
to the NBB Revolving Credit Borrowing requested herein: $                     

(c)                                  NBB Letters of Credit outstanding prior to
the NBB Revolving Credit Borrowing requested herein:  $                     

 2
 

(d)                                 Principal amount of NBB Revolving Credit
Loans available to be borrowed (1(a) minus the sum of 1(b) and 1(c)): $                     

2.                                       Amount of NBB Revolving Credit Borrowing: $                     

3                                          Requested date of NBB Revolving Credit
Borrowing:                                ,
200  .

4.                                       Requested Type of Loan for NBB Revolving
Credit Borrowing and applicable

Dollar amount:

(a)                                  Base Rate Loan for $                     

(b)                                 Eurodollar Rate Loan with Interest Period of:

	
  

  	
  (i)

  	
  one month for

  	
  $                     

  
	
   

  	
  (ii)

  	
  two months for

  	
  $                     

  
	
   

  	
  (iii)

  	
  three months for

  	
  $                     

  
	
   

  	
  (iv)

  	
  six months for

  	
  $                     

  

 

The undersigned hereby
certifies that the following statements will be true on the date of the
proposed Borrowing(s) after giving effect thereto and to the application of the
proceeds therefrom:

(a)                                  the representations and warranties of the
Borrower contained in Article
V of the Agreement are true and correct as though made on and as
of such date (except such representations and warranties which expressly refer
to an earlier date, which are true and correct as of such earlier date);

(b)                                 if applicable, the amount of the requested
Revolving Credit Borrowing, when added to Revolving Credit Loans outstanding
prior to the requested Revolving Credit Borrowing and Letters of Credit outstanding
prior to the requested Revolving Credit Borrowing, will not exceed the
Borrowing Base referred to in Section 1.3.
above;

(c)                                  if applicable, the amount of the requested
Unit Acquisition Borrowing, when added to Unit Acquisition Loans outstanding prior
to the requested Unit Acquisition Borrowing, will not exceed the Aggregate Unit
Acquisition Commitment referred to in Section II.1(a)
above;

(d)                                 no Default or Event of Default has occurred
and is continuing, or would result from such proposed Borrowing(s);

(e)                                  if a Borrowing of a Unit Acquisition Loan or
Borrowing of a Revolving Credit Loan to be funded out of an increase in the
Aggregate Revolving Credit Commitment pursuant to
Section 2.13 is requested hereby, Borrower represents and
warrants that either (i) the MLP Operating Subsidiary or any of its
Subsidiaries has made Permitted Acquisitions (as defined in the MLP Credit
Agreement) in excess of $40,000,000
or (ii) the MLP Operating Subsidiary or any of its Subsidiaries has made
Capital Expenditures(as defined in the MLP Credit Agreement) in excess of $40,000,000; and

(f)                                    if a Borrowing of a NBB Revolving Credit Loan
is to be funded, Borrower certifies that (i) the sole purpose of such NBB
Revolving Credit Loan is to enable the Borrower to meet margin requirements
under Swap Contracts and (ii) after giving pro forma effect to such requested
NBB Revolving Credit Loan, the Collateral Coverage Ratio shall be at least 3.5
to 1.0.

The Borrowing requested
herein complies with Sections
2.01, Sections
2.02 and 2.03
of the Agreement, as applicable. 
Accompanying this Borrowing Notice is a Statement of Purpose For an

 3
 

Extension
of Credit Secured by Margin Stock (Federal Reserve Form U-1) duly executed by a
Responsible Officer of the Borrower which is true and correct in all respects.

	
   

  	
  MARKWEST HYDROCARBON, INC.,

  
	
   

  	
  a Delaware
  corporation, as Borrower

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Name:

  	
   

  
	
   

  	
  Title:

  	
   

  
					

 

 4

EXHIBIT A-2

FORM OF
CONVERSION/CONTINUATION NOTICE

Date:                          ,           

TO:                          Royal Bank of Canada, as Administrative Agent

Ladies and Gentlemen:

Reference is made to that
certain Second Amended and Restated Credit Agreement, dated as of August 18,
2006 (as amended, restated, extended, supplemented or otherwise modified in
writing from time to time, the “Agreement;” the terms defined therein being used herein
as therein defined), among MarkWest Hydrocarbon, Inc., a Delaware corporation
(the “Borrower”),
Royal Bank of Canada, as Administrative Agent, and the Lenders from time to
time party thereto.

The undersigned hereby
requests:

I.                                         REVOLVING CREDIT FACILITY

	
   

  	
  1.

  	
  Amount of [conversion] [continuation]of Revolving Credit
  Loans: $

  	
                     

  
	
   

  
	
   

  	
  2.

  	
  Existing rate:

  	
  Check applicable blank

  	
   

  
	
   

  
	
   

  	
   

  	
  (a)

  	
  Base Rate

  	
  o

  	
   

  
	
   

  
	
   

  	
   

  	
  (b)

  	
  Eurodollar Rate Loan with

  
	
   

  	
   

  	
   

  	
  Interest Period of:

  
	
   

  	
   

  	
   

  	
   

  
	
  

  	
  (i)

  	
  one month

  	
  o

  	 

	
   

  	
  (ii)

  	
  two months

  	
  o

  	 

	
   

  	
  (iii)

  	
  three months

  	
  o

  	 

	
   

  	
  (iv)

  	
  six months

  	
  o

  	 

										

 

3.                                       If a Eurodollar Rate Loan, date of the last
day of the Interest Period for such Loan:             ,
200  .

The Revolving Credit Loan described above is to be [converted]
[continued] as follows:

4.                                       Requested date of [conversion]
[continuation]of Revolving Credit Loan:                              ,
200  .

5.                                       Requested Type of Loan and applicable Dollar
amount:

(a)                                  Base Rate Loan for $                   

(b)                                 Eurodollar Rate Loan with Interest Period of:

	
  

  	
  (i)

  	
  one month for

  	
  $                     

  
	
   

  	
  (ii)

  	
  two months for

  	
  $                     

  
	
   

  	
  (iii)

  	
  three months for

  	
  $                     

  
	
   

  	
  (iv)

  	
  six months for

  	
  $                     

  

 

 1
 

II.                                     UNIT ACQUISITION FACILITY

	
  

  	
  1.

  	
  Amount of [conversion] [continuation] Unit
  Acquisition Loan: $

  	
                     

  
	
   

  
	
   

  	
  2.

  	
  Existing rate:

  	
  Check applicable blank

  	
   

  
	
   

  
	
   

  	
   

  	
  (a)

  	
  Base Rate

  	
  o

  	
   

  
	
   

  
	
   

  	
   

  	
  (b)

  	
  Eurodollar Rate Loan with

  
	
   

  	
   

  	
   

  	
  Interest Period of:

  
	
   

  	
   

  	
   

  	
   

  
	
  

  	
  (i)

  	
  one month

  	
  o

  	 

	
   

  	
  (ii)

  	
  two months

  	
  o

  	 

	
   

  	
  (iii)

  	
  three months

  	
  o

  	 

	
   

  	
  (iv)

  	
  six months

  	
  o

  	 

	
   

  	
   

  	
   

  	
   

  	 

	
   

  	
  3.

  	
  If a Eurodollar Rate Loan,
  date of the last day of the Interest Period for such Loan:                 ,
  200  .

  
	
   

  
	
   

  	
  The Unit Acquisition Loan
  described above is to be [converted] [continued] as follows:

  
	
   

  	
   

  
	
   

  	
  4.

  	
  Requested date of
  [conversion] [continuation]of Unit Acquisition Loan:                               ,
  200  .

  
	
   

  	
   

  	
   

  
	
   

  	
  5.

  	
  Requested Type of Loan and
  applicable Dollar amount:

  
	
   

  
	
   

  	
   

  	
  (a)

  	
  Base Rate Loan for $                   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  (b)

  	
  Eurodollar Rate Loan with
  Interest Period of:

  
	
   

  	
   

  	
   

  	
   

  	 

	
  

  	
  (i)

  	
  one month for

  	
  $                     

  	 

	
   

  	
  (ii)

  	
  two months for

  	
  $                     

  	 

	
   

  	
  (iii)

  	
  three months for

  	
  $                     

  	 

	
   

  	
  (iv)

  	
  six months for

  	
  $                     

  	 

	
   

  	
   

  	
   

  	
   

  	 

	
   II.                                  NBB REVOLVING CREDIT FACILITY

  	
   

  	 

	
   

  	
   

  	 

	
  

  	
  1.

  	
  Amount of [conversion] [continuation] NBB Revolving
  Credit Loan: $

  	
                     

  
	
   

  
	
   

  	
  2.

  	
  Existing rate:

  	
  Check applicable blank

  	
   

  
	
   

  
	
   

  	
   

  	
  (a)

  	
  Base Rate

  	
  o

  	
   

  
	
   

  
	
   

  	
   

  	
  (b)

  	
  Eurodollar Rate Loan with

  
	
   

  	
   

  	
   

  	
  Interest Period of:

  
	
   

  	
   

  	
   

  	
   

  
	
  

  	
  (i)

  	
  one month

  	
  o

  	 

	
   

  	
  (ii)

  	
  two months

  	
  o

  	 

	
   

  	
  (iii)

  	
  three months

  	
  o

  	 

	
   

  	
  (iv)

  	
  six months

  	
  o

  	 

											

 

 

 2
 

3.                                       If a Eurodollar Rate Loan, date of the last
day of the Interest Period for such Loan:                               ,
200  .

The NBB Revolving Credit Loan described above is to be [converted]
[continued] as follows:

4.                                       Requested date of [conversion]
[continuation]of NBB Revolving Credit Loan:                   
, 200  .

5.                                       Requested Type of Loan and applicable Dollar
amount:

	
  

  	
   

  	
  (a)

  	
  Base Rate Loan for $                   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  (b)

  	
  Eurodollar Rate Loan with
  Interest Period of:

  
	
   

  	
   

  	
   

  	
   

  
	
  

  	
  (i)

  	
  one month for

  	
  $                     

  	 

	
   

  	
  (ii)

  	
  two months for

  	
  $                     

  	 

	
   

  	
  (iii)

  	
  three months for

  	
  $                     

  	 

	
   

  	
  (iv)

  	
  six months for

  	
  $                     

  	 

 

The [conversion]
[continuation] requested herein complies with Sections 2.01  and 2.03  of the Agreement, as applicable.

	
   

  	
  MARKWEST ENERGY HYDROCARBON,
  INC.,

  
	
   

  	
  a Delaware
  corporation, as Borrower

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Name:

  	
   

  
	
   

  	
  Title:

  	
   

  
					

 

 3

EXHIBIT B-3

FORM OF NBB
REVOLVING CREDIT NOTE

$                                                                                                                                                                                                    ,
200  

FOR VALUE RECEIVED, the
undersigned (the “Borrower”),
hereby promises to pay to the order of                                
(the “Lender”),
on the Maturity Date (as defined in the Credit Agreement referred to below) the
principal amount of                       Dollars
($                       ),
or such lesser principal amount of NBB Revolving Credit Loans made by Lender
under the Credit Agreement due and payable by the Borrower to the Lender on the
Maturity Date under that certain Second Amended and Restated Credit Agreement
dated as of August 18, 2006 (as amended, restated, extended, supplemented or
otherwise modified in writing from time to time, the “Credit Agreement”;
the terms defined therein being used herein as therein defined), among the
Borrower, the Lenders from time to time party thereto, and Royal Bank of
Canada, as Administrative Agent.

The Borrower promises to pay
interest on the unpaid principal amount of each NBB Revolving Credit Loan from
the date of such NBB Revolving Credit Loan until such principal amount is paid
in full, at such interest rates, and at such times as are specified in the
Credit Agreement.  All payments of
principal and interest shall be made to the Administrative Agent for the
account of the Lender in Dollars in immediately available funds to the account
designated by the Administrative Agent in the Credit Agreement.  If any amount is not paid in full when due
hereunder, such unpaid amount shall bear interest, to be paid upon demand, from
the due date thereof until the date of actual payment (and before as well as
after judgment) computed at the per annum rate set forth in the Credit
Agreement.

This NBB Revolving Credit
Note is one of the NBB Revolving Credit Notes referred to in the Credit
Agreement, is entitled to the benefits thereof and is subject to optional and
mandatory prepayment in whole or in part as provided therein.  This NBB Revolving Credit Note is also entitled
to the benefits of each Guaranty.  Upon
the occurrence of one or more of the Events of Default specified in the Credit
Agreement, all amounts then remaining unpaid on this NBB Revolving Credit Note
shall become, or may be declared to be, immediately due and payable all as
provided in the Credit Agreement.  NBB
Revolving Credit Loans made by the Lender shall be evidenced by one or more
loan accounts or records maintained by the Lender in the ordinary course of
business.  The Lender may also attach schedules
to this NBB Revolving Credit Note and endorse thereon the date, amount and
maturity of its NBB Revolving Credit Loans and payments with respect thereto.

This NBB Revolving Credit
Note is a Loan Document and is subject to Section 10.10 of the Credit Agreement, which
is incorporated herein by reference the same as if set forth herein verbatim.

The Borrower, for itself,
its successors and assigns, hereby waives diligence, presentment, protest and
demand and notice of protest, notice of intent to accelerate, notice of
acceleration, demand, dishonor and non-payment of this NBB Revolving
Credit Note.

 1
 

THIS
NBB REVOLVING CREDIT NOTE SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH
THE LAWS OF THE STATE OF TEXAS.

	
   

  	
  MARKWEST HYDROCARBON, INC.,

  
	
   

  	
  a Delaware
  corporation, as Borrower

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  	
   

  
	
   

  	
  Name:

  	
   

  	
   

  
	
   

  	
  Title:

  	
   

  	
   

  

 

 2

EXHIBIT C-1

FORM OF COMPLIANCE CERTIFICATE

(Pursuant to Section 6.02  of the Credit Agreement)

Financial Statement Date:            ,
    

To:          Royal
Bank of Canada, as Administrative Agent

Ladies and Gentlemen:

Reference is made to that
certain Second Amended and Restated Credit Agreement, dated as of August 18,
2006 (as amended, restated, extended, supplemented or otherwise modified in
writing from time to time, the “Credit  Agreement;” the terms
defined therein being used herein as therein defined), MarkWest Hydrocarbon,
Inc., a Delaware corporation (the “Borrower”), the Lenders from time to time
party thereto, and Royal Bank of Canada, as Administrative Agent. Capitalized
terms used herein but not defined herein shall have the meaning set forth in
the Credit Agreement.

The undersigned Responsible
Officer hereby certifies as of the date hereof that he/she is the                                            
of the Borrower, and that, as such, he/she is authorized to execute and deliver
this Certificate to the Administrative Agent on the behalf of the Borrower, and
that:

[Use the following for
fiscal year-end financial statements]

Attached hereto as Schedule 1  are the year-end audited stand
alone financial statements of the Borrower required by Section 6.01(a)  of the Credit Agreement for the fiscal
year of the Borrower ended as of the above date, together with the report and
opinion of an independent certified public accountant required by such section;
and

[Use the following for
fiscal quarter-end financial statements]

Attached hereto as Schedule 1  are, the unaudited stand alone financial
statements of the Borrower required by Section 6.01(b) of the Credit Agreement for
the first three fiscal quarters of the Borrower ended as of the above date,
together with a certificate of a Responsible Officer of the Borrower stating
that such financial statements fairly present the financial condition, results
of operations and cash flows of the Borrower for such fiscal quarter in
accordance with GAAP as at such date and for such period, subject only to
normal year-end audit adjustments and the absence of footnotes.

[Use the following for both
fiscal year-end and quarter-end financial statements]

1.             The undersigned has reviewed and is familiar with the
terms of the Credit Agreement and has made, or has caused to be made under
his/her supervision, a detailed review of the transactions and condition
(financial or otherwise) of the Borrower during the accounting period covered
by the attached financial statements.

2.             A review of the activities of the Borrower during such
fiscal period has been made under the supervision of the undersigned with a
view to determining whether during such fiscal period the Borrower performed
and observed all its Obligations under the Loan Documents, and no Default or
Event of Default has occurred and is continuing except as follows (list of each such Default or Event of
Default and include the information required by Section 6.03 of the Credit Agreement):

 1
 

3.             The covenant analyses and information set forth on Schedule 3 attached
hereto are true and accurate on and as of the date of this Certificate.

IN WITNESS WHEREOF, the
undersigned has executed this Certificate as of            ,
200 .

	
  

  	
   

  	
  MARKWEST HYDROCARBON, INC.

  
	
   

  	
   

  	
  a Delaware corporation, as Borrower

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
   

  
	
   

  	
   

  	
  Name:

  	
   

  
	
   

  	
   

  	
  Title:

  	
   

  
					

 

 2
 

For
the Quarter/Year ended                      (“Statement Date”)

SCHEDULE 3

to the Compliance Certificate

($ in 000’s)

	
  I. 

  	
  Section 7.04 – Indebtedness

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  A.

  	
  Obligations existing under any Swap Contract
  permitted by Section 7.04(c)

  	
  $                 

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  B.

  	
  Outstanding
  Principal Amount of Purchase Money Indebtedness for fixed or capital assets
  permitted by Section
  7.04(d)(may not exceed $1,000,000)

  	
  $                 

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  C.

  	
  Outstanding
  Principal Amount of other Indebtedness permitted by Section 7.04(e) (may not exceed $1,000,000)

  	
  $                 

  
	
   

  	
   

  	
   

  	
   

  
	
  II.

  	
  Section 7.08 – Restricted
  Payments; Distributions and Redemptions

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  A.

  	
  Cash and Cash
  Equivalents as of the Statement Date.

  	
  $                 

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  B.

  	
  Borrower’s
  Consolidated Net Income commencing with the fiscal quarter beginning July 1,
  2006 through and including the Statement Date:

  	
  $                 

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  C.

  	
  50% of Line
  II.B:

  	
  $                 

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  D.

  	
  Total of Line
  II.A +Line II.C:

  	
  $                 

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  E.

  	
  Total of
  Restricted Payments made on or after July 1, 2006 through and including
  Statement Date:

  	
  $                 

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  F.

  	
  Excess of Line
  II.D over Line II.E:

  	
  $                 

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  G.

  	
  Is Line II.D
  greater than Line II.E? Is so, to the extent of such excess Borrower make a
  Restricted Payment if no Default or Event of Default exists

  	
  Yes/No 

  Amount of excess: $     

  
	
   

  	
   

  	
   

  	
   

  
	
  III.

  	
  Section 7.15(a) – Leverage
  Ratio

  	
   

  
	
   

  	
   

  
	
   

  	
  A.

  	
  Consolidated Funded
  Debt (borrowed money indebtedness, Capital Leases, and Synthetic Leases)

  	
  $                 

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  B.

  	
  Consolidated
  EBITDA for four consecutive fiscal quarters ending on the Statement Date  (“Subject Period”) (see
  Credit Agreement definition of “Consolidated
  EBITDA”):

  	
  $                 

  
						

 

 3
 

 

	
  

  	
  C.

  	
  Leverage Ratio
  (Line III.A. divided by Line III.B)

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  D.

  	
  Is Leverage
  Ratio greater than 4.0 to 1.0?

  	
  Yes/No

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  E.

  	
  As an
  alternative to the preceding Leverage Ratio in Line II.D, if more than
  $5,000,000 is outstanding under the Unit Acquisition Facility OR if the
  Aggregate Revolving Credit Commitment has been increased pursuant to Section
  2.13, is the Leverage Ratio greater than 5.50 to 1.0?

  	
  Yes/No

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  F.

  	
  As an
  alternative to the Leverage Ratios in Lines II.D and II.E, if more than
  $5,000,000 is outstanding under the Unit Acquisition Facility OR if more than
  $5,000,000 of Revolving Credit Loans funded out of an increase in the
  Revolving Credit Commitment pursuant to Section 2.13 is outstanding AND 9
  months or more (but not more than 18 months) have elapsed since the date of
  funding such Loans, is the Leverage Ratio greater than 4.75 to 1.0?

  	
  Yes/No

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  G.

  	
  As an
  alternative to the Leverage Ratios in Lines II.D, II.E and II.F, if more than
  $5,000,000 is outstanding under the Unit Acquisition Facility OR if more than
  $5,000,000 of Revolving Credit Loans funded out of an increase in the
  Revolving Credit Commitment pursuant to Section 2.13 is outstanding AND 18
  months or more have elapsed since the date of funding such Loans, is the
  Leverage Ratio greater than 4.00 to 1.0?

  	
  Yes/No

  
	
   

  	
   

  	
   

  	
   

  
	
  IV. 

  	
  Section
  7.15(b) — Minimum Consolidated Tangible Net Worth (as
  calculated pursuant to Credit Agreement)

  	
   

  
	
   

  	
   

  
	
   

  	
  A.

  	
  Initial Required
  Consolidated Tangible Net Worth

  	
  $30,000,000

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  B.

  	
  50% of
  Consolidated Net Income after July 1, 2006:

  	
  $                 

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  C.

  	
  100% of proceeds
  of all equity issued subsequent to Second Restatement Date:

  	
  $                 

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  D.

  	
  Sum of Line IV.A
  + Line IV.B + Line IV.B):

  	
  $                 

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  E.

  	
   Consolidated Tangible Net Worth as of
  Statement Date:

  	
  $                 

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
  Yes/No

  

 

 4
 

 

	
  

  	
  F.

  	
  Is Line IV.E
  equal to or greater than Line IV.B?

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
  V.

  	
  Section 7.16 –
  Minimum Collateral Coverage Ratio (as calculated pursuant to Credit
  Agreement)

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  A.

  	
  Market Price of
  Common MLP Units as of Statement Date pledged as Collateral securing
  Obligations

  	
  $                 

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  B.

  	
  Market Price of
  Subordinated MLP Units as of Statement Date pledged as Collateral securing
  Obligations

  	
  $                 

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  C.

  	
  Midstream
  Accounts Receivable as of Statement Date pledged as Collateral securing
  Obligations

  	
  $                 

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  D.

  	
  Midstream
  Inventory as of Statement Date pledged as Collateral securing Obligations

  	
  $                 

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  E.

  	
  Sum of Line V.A.
  + Line V.B. + Line V.C + Line V.D

  	
  $                 

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  F.

  	
  Outstanding
  Amount of Revolving Credit Loans as of Statement Date

  	
  $                 

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  G.

  	
  L/C Obligations
  as of Statement Date

  	
  $                 

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  H.

  	
  Outstanding
  Amount of Unit Acquisition Loans as of Statement Date

  	
  $                 

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  I.

  	
  Outstanding
  Amount of NBB Revolving Credit Loans as of Statement Date

  	
  $                 

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  J.

  	
  NBB L/C
  Obligations as of Statement Date

  	
  $                 

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  K.

  	
  Sum of Line V.F
  plus Line V.G plus Line V.H plus Line V.I plus Line V.J

  	
  $                 

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  L.

  	
  Is ratio of Line
  V.E to Line V.K at least 2:1?

  	
  Yes/No

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  M.

  	
  If there are any
  NBB Revolving Credit Loans or NBB Letters of Credit outstanding and after
  giving pro forma effect to any requested NBB Revolving Credit Loans or NBB
  Letters of Credit, is the Collateral Coverage Ratio greater than 3.5 to 1.0?

  	
  Yes/No

  

 

 5

EXHIBIT C-2

FORM OF BORROWING BASE REPORT

Borrowing Base
Report

MARKWEST HYDROCARBON, INC. 

Monthly Borrowing Base Report 

For the Month Ending                           

Calculation of
Monthly Borrowing Base and Excess Revolving Credit Facility Availability

	
  A.

  	
   

  	
  Eligible Midstream Accounts Receivable

  	
   

  	
  $

  	
   

  	
  X

  	
   

  	
  75%

  	
   

  	
  $

  
	
  B.

  	
   

  	
  Hedged Eligible Midstream Inventory

  	
   

  	
  $

  	
   

  	
  X

  	
   

  	
  85%

  	
   

  	
  $

  
	
  C.

  	
   

  	
  Unhedged Eligible Midstream Inventory

  	
   

  	
  $

  	
   

  	
  X

  	
   

  	
  75%

  	
   

  	
  $

  
	
  D.

  	
   

  	
  Total Eligible Accounts Receivable and Inventory
  (A+B+C)

  	
   

  	
   

  	
   

  	
   

  	
   

  	
  $

  
	
  E.

  	
   

  	
  Borrowing Base (lower of (i) D or (ii) Revolving
  Credit Commitment (maximum $40,000,000 subject to increase following the
  Revolving Credit Commitment Increase Effective Date) minus Borrowing Base
  Liquidity Reserve

  	
  $

  
	
  F.

  	
   

  	
  Outstanding Amount of Revolving Credit Loans

  	
  $

  
	
  G.

  	
   

  	
  Outstanding Amount of L/C Obligations

  	
  $

  
	
  H.

  	
   

  	
  Revolving Credit Facility Usage (F+G)

  	
  $

  
	
  I.

  	
   

  	
  Excess Revolving Credit Facility Availability (E
  minus H)

  	
  $

  

 

Collateral Coverage Ratio

MARKWEST HYDROCARBON, INC.

Collateral Coverage Ratio Analysis

As
of borrowing date:                           

	
  A.

  	
   

  	
  Market Price of Common MLP Units

  	
   

  	
  $

  
	
  B.

  	
   

  	
  Market Price of Subordinated MLP Units

  	
   

  	
  $

  
	
  C.

  	
   

  	
  Midstream Accounts Receivable

  	
   

  	
  $

  
	
  D.

  	
   

  	
  Midstream Inventory

  	
   

  	
  $

  
	
  E.

  	
   

  	
  Total Collateral (A+B+C+D)

  	
   

  	
  $

  
	
  F.

  	
   

  	
  Outstanding Amount of Revolving Credit Loans

  	
   

  	
  $

  
	
  G.

  	
   

  	
  Outstanding Amount of L/C Obligations

  	
   

  	
  $

  
	
  H.

  	
   

  	
  Outstanding Amount of Unit Acquisition Loans

  	
   

  	
  $

  
	
  I.

  	
   

  	
  Outstanding Amount of NBB Revolving Credit Loans

  	
   

  	
  $

  
	
  J.

  	
   

  	
  Outstanding Amount of NBB L/C Obligations

  	
   

  	
  $

  
	
  K.

  	
   

  	
  Total Outstanding Loans and L/C Obligations and NBB
  L/C Obligations (F+G+H+I+J)

  	
   

  	
  $

  
	
  L.

  	
   

  	
  Requested Amount of Loans and L/C Credit Extension
  and NBB L/C Credit Extension

  	
   

  	
  $

  
	
  M.

  	
   

  	
  Is ratio of Line E at least 2:1 over the sum of
  Lines K +L?

  	
   

  	
  Yes/No

  

 

- BORROWER
CERTIFICATION -

Attached hereto as Schedule 1 is a
detailed aged schedule of all Midstream Accounts Receivable as of the date
specified in this Borrowing  Base Report,
listing face amounts and dates of invoices of each such Midstream Accounts
Receivable and the name and address of each account debtor obligated on such
Midstream Accounts Receivable (and, if requested by Administrative Agent,
copies of invoices, credit reports, and any other matters and information
relating to the Midstream Accounts Receivable).

 1
 

Attached hereto as Schedule 2 is a
schedule of Midstream Inventory, setting forth the location, volume, cost,
market price and hedged price of all such Midstream Inventory.

Attached hereto as Schedule 3 is a
summary aged listing of Borrower’s accounts payable and an aged list of the ten
(10) largest accounts payable.

The undersigned hereby warrants to Royal Bank of
Canada, as Administrative Agent, that this Borrowing Base Report is a correct
statement regarding the Midstream Accounts Receivable and Midstream Inventory
of Borrower and its Domestic MarkWest Inc. Subsidiaries and that the
reconciliation figures are fully and correctly set forth.  Capitalized terms used but not defined herein
shall have the meanings given such terms in the Second Amended and Restated
Credit Agreement dated August 18, 2006 among MarkWest Hydrocarbon, Inc., the
lenders party thereto and Royal Bank of Canada, as Administrative Agent.

	
  

  	
  MARKWEST HYDROCARBON, INC.

  	 

	
   

  	
   

  	
   

  	 

	
   

  	
  By:

  	
   

  	
   

  	 

	
   

  	
  Name:

  	
   

  
	
   

  	
  Title:

  	
  Chief Financial Officer/Treasurer

  
						

 

 2

EXHIBIT F

FORM OF NBB BORROWING CERTIFICATE

(Pursuant to Section 2.15(a)of the Credit Agreement)

Certificate Date:                        ,
          

To:                           Royal Bank of Canada, as Administrative Agent

Ladies and Gentlemen:

Reference is made to that
certain Second Amended and Restated Credit Agreement, dated as of August 18,
2006 (as amended, restated, extended, supplemented or otherwise modified in
writing from time to time, the “Credit  Agreement;” the terms
defined therein being used herein as therein defined), MarkWest Hydrocarbon,
Inc., a Delaware corporation (the “Borrower”), the Lenders from time to time
party thereto, and Royal Bank of Canada, as Administrative Agent. Capitalized
terms used herein but not defined herein shall have the meaning set forth in
the Credit Agreement.

The undersigned Responsible
Officer hereby certifies as of the date hereof that he/she is the                                                       
of the Borrower, and that, as such, he/she is authorized to execute and deliver
this Certificate to the Administrative Agent on the behalf of the Borrower, and
that:

Attached hereto as Schedule 1  is
a listing of all of the Borrower’s existing Swap Contracts and the margin
requirements under each.  As of the date
of this Certificate, the Outstanding NBB Revolving Credit Loans are no greater
than the aggregate margin requirements set forth on Schedule 1.

IN WITNESS WHEREOF, the
undersigned has executed this Certificate as of                        ,
200 .

	
   

  	
  MARKWEST HYDROCARBON, INC.

  
	
   

  	
  a Delaware corporation, as Borrower

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Name:

  	
   

  
	
   

  	
  Title:

  	
   

  
					

 

 1
 

For the month ended                                                 (“Certificate Date”)

SCHEDULE 1

to the NBB Borrowing Certificate

	
  I.   Swap Contracts (proposed
  and/or currently in effect), with name of counterparty, material terms, etc.

  	
   

  	
  Margin
  Requirement under

  Swap Contracts

  
	
       1.

  	
   

  	
  $

  
	
       2.

  	
   

  	
  $

  
	
       3.

  	
   

  	
  $

  
	
  II.  Total
  Margin Requirements

  	
   

  	
  $

  
	
  III.  Outstanding NBB Revolving Credit Loans

  	
   

  	
  $

  
	
  IV.  Outstanding
  NBB Letters of Credit

  	
   

  	
  $

  
	
  V.  Proposed
  NBB Revolving Credit Borrowing (if any)

  	
   

  	
  $

  
	
  VI  Proposed
  NBB Letter of Credit (if any)

  	
   

  	
  $

  
	
  VII. Sum of Lines III, IV, V and VI

  	
   

  	
  $

  
	
  VIII.  Is Line
  VII equal to or less than Line II?

  	
   

  	
  Yes/No

  

 

Collateral
Coverage Ratio

MARKWEST HYDROCARBON, INC.

Collateral Coverage Ratio Analysis

As
of Certificate Date:                 

	
  A.

  	
   

  	
  Market Price of Common MLP Units

  	
   

  	
  $                    

  
	
  B.

  	
   

  	
  Market Price of Subordinated MLP Units

  	
   

  	
  $                    

  
	
  C.

  	
   

  	
  Midstream Accounts Receivable

  	
   

  	
  $                    

  
	
  D.

  	
   

  	
  Midstream Inventory

  	
   

  	
  $                    

  
	
  E.

  	
   

  	
  Total Collateral (A+B+C+D)

  	
   

  	
  $                    

  
	
  F.

  	
   

  	
  Outstanding Amount of Revolving Credit Loans

  	
   

  	
  $                    

  
	
  G.

  	
   

  	
  Outstanding Amount of L/C Obligations

  	
   

  	
  $                    

  
	
  H.

  	
   

  	
  Outstanding Amount of Unit Acquisition Loans

  	
   

  	
  $                    

  
	
  I.

  	
   

  	
  Outstanding Amount of NBB Revolving Credit Loans

  	
   

  	
  $                    

  
	
  J.

  	
   

  	
  Outstanding Amount of NBB L/C Obligations

  	
   

  	
  $                    

  
	
  K.

  	
   

  	
  Total Outstanding Loans and L/C Obligations and NBB
  L/C Obligations (F+G+H+I+J)

  	
   

  	
  $                    

  
	
  L.

  	
   

  	
  Requested Amount of Loans and L/C Credit Extension
  and NBB L/C Credit Extension

  	
   

  	
  $                    

  
	
  M.

  	
   

  	
  Is ratio of Line E at least 3.5:1.0 over the sum of
  Lines K +L?

  	
   

  	
  Yes/No

  

 

 2Exhibit
10.1

priceline.com
Incorporated

Annual
Bonus Plan

TABLE OF CONTENTS

	
  

  	
   

  	
   

  	
   

  	
  Page

  
	
  Section 1 - Establishment Of the Plan

  	
   

  	
  1

  
	
  1.01

  	
   

  	
  Purpose

  	
   

  	
  1

  
	
  1.02

  	
   

  	
  Effective Date

  	
   

  	
  1

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
  Section 2 - Definitions

  	
   

  	
  1

  
	
  2.01

  	
   

  	
  Bonus

  	
   

  	
  1

  
	
  2.02

  	
   

  	
  Bonus Classification

  	
   

  	
  1

  
	
  2.03

  	
   

  	
  Bonus Formula

  	
   

  	
  1

  
	
  2.04

  	
   

  	
  Board

  	
   

  	
  1

  
	
  2.05

  	
   

  	
  CEO

  	
   

  	
  1

  
	
  2.06

  	
   

  	
  Committee

  	
   

  	
  2

  
	
  2.07

  	
   

  	
  Corporation

  	
   

  	
  2

  
	
  2.08

  	
   

  	
  Eligible Employee

  	
   

  	
  2

  
	
  2.09

  	
   

  	
  Entitled Employee

  	
   

  	
  2

  
	
  2.10

  	
   

  	
  Performance Measure

  	
   

  	
  2

  
	
  2.11

  	
   

  	
  Performance Period

  	
   

  	
  2

  
	
  2.12

  	
   

  	
  Plan

  	
   

  	
  2

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
  Section 3 - Participation

  	
   

  	
  3

  
	
  3.01

  	
   

  	
  Participation Requirements

  	
   

  	
  3

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
  Section 4 - Bonus

  	
   

  	
  3

  
	
  4.01

  	
   

  	
  Eligibility

  	
   

  	
  3

  
	
  4.02

  	
   

  	
  Determination of Bonuses

  	
   

  	
  3

  
	
  4.03

  	
   

  	
  Limitation of Bonuses and General Discretion

  	
   

  	
  3

  
	
  4.04

  	
   

  	
  Bonus Payments

  	
   

  	
  4

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
  Section 5 - Administration of the Plan

  	
   

  	
  4

  
	
  5.01

  	
   

  	
  Administration

  	
   

  	
  4

  
	
  5.02

  	
   

  	
  Right to Receive Payment

  	
   

  	
  4

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
  Section 6 - Provisions 

  	
   

  	
  4

  
	
  6.01

  	
   

  	
  Amendment or Termination

  	
   

  	
  4

  
	
  6.02

  	
   

  	
  Effect of Amendment or Termination

  	
   

  	
  5

  
	
  6.03

  	
   

  	
  No Enlargement of Contractual Rights

  	
   

  	
  5

  
	
  6.04

  	
   

  	
  Interpretation

  	
   

  	
  5

  
	
  6.05

  	
   

  	
  Withholding of Taxes

  	
   

  	
  5

  
	
  6.06

  	
   

  	
  Binding on Successors

  	
   

  	
  5

  
	
  6.07

  	
   

  	
  Currency

  	
   

  	
  5

  

 

SECTION 1  — 
Establishment Of the Plan

1.01  Purpose

This Plan is established for the purpose of rewarding employees on an
annual basis for their efforts and contributions in the attainment of certain
performance measures that contribute materially to the success of the business
interests of priceline.com Incorporated.

1.02  Effective Date

Subject to Section 7.02 (Amendment or Termination), this Plan shall be
effective on and after January 30, 2007.

SECTION 2  — 
Definitions

The following terms, when capitalized, shall be defined as follows:

2.01  Bonus

“Bonus” means, as to an Eligible Employee, a cash payment determined
pursuant to the Bonus Formula, as determined in Section 4.

2.02  Bonus Classification

“Bonus Classification” means, for any Performance Period, a
classification of employees to which the Committee assigns a Bonus Formula.

2.03  Bonus
Formula

“Bonus Formula” means, as to any Performance Period, the formula
established by the Committee with respect to the CEO, and by the CEO or the
Committee with respect to other Entitled Employees, to determine the amounts
available for Bonuses and the Bonus amounts, if any, to be paid to Entitled
Employees based upon such compensation as the Committee may determine and the
level of achievement of targeted goals for the selected Performance
Measures.  The formula may differ from
Entitled Employee to Entitled Employee or from Bonus Classification to Bonus
Classification.

2.04  Board

“Board” means the Board of Directors of priceline.com Incorporated.

2.05  CEO

“CEO” means the Chief Executive Officer of priceline.com Incorporated.

 1
 

 

2.06  Committee

“Committee” means the Compensation Committee of the Board.

2.07  Corporation

“Corporation” means priceline.com Incorporated and its direct and
indirect subsidiaries.

2.08  Eligible Employee

“Eligible Employee” means an employee who has satisfied the eligibility
requirements set out in Section 4.01 (Eligibility).

2.09  Entitled Employee

“Entitled Employee” means the CEO and any Eligible Employee who is
recommended by the CEO and approved by the Committee to participate in this
Plan.

2.10  Performance Measure

“Performance Measure” means, for any Performance Period, any
performance criteria as specified and approved by the Committee.  The performance criteria may be applied either
individually, alternatively, or in any combination and measured on an absolute
basis or relative to a pre-established target as may be specified and approved
by the Committee.  The performance
criteria may include the following measures, among others:  return on invested capital, net operating
profit (before or after tax), operating profit margin, gross margin, operating
profit, earnings before income taxes, earnings before interest, income taxes,
depreciation and amortization (“EBITDA”), “pro forma” EBITDA, “pro forma” net
income per share (on a United States Generally Accepted Accounting Principles (“GAAP”)
or non-GAAP basis), growth in any of the foregoing measures, stock price,
return on equity or average shareholders’ equity, total shareholder return,
growth in shareholder value relative to a moving average of a selected index,
return on capital, return on assets or net assets, return on investment,
economic value added, market shares, overhead or other expense reduction,
credit rating, strategic plan development and implementation, succession plan
development and implementation, improvement in workforce, diversity, customer
indicators, improvements in productivity, attainment of objective operating
goals and employee metrics.

2.11  Performance
Period

“Performance Period” means the period of time designated by the
Committee during which the Performance Measures are measured for purposes of
determining a Bonus.

2.12  Plan

“Plan” means this Annual Bonus Plan, as amended from time to time.

 2
 

 

SECTION 3  —  Participation

3.01  Participation Requirements

Participation in the Plan is limited to Eligible Employees.

SECTION 4  — 
Bonus

4.01  Eligibility

An employee of the Corporation who is employed for at least three
months during a year, and who is in the employ of the Corporation at the time
Bonus amounts are paid shall become an Eligible Employee.  The Committee may determine that employees
not meeting the above criteria are Eligible Employee’s in their sole
discretion.

4.02  Determination of Bonuses

Within 60 days after the end of the year, the Committee shall designate
and approve the following:

(a)                                  Performance Period;

(b)                                 Positions or names of employees, including
the CEO, who will be Entitled Employees for the Performance Period;

(c)                                  Targeted goals for selected Performance
Measures during the Performance Period; and

(d)                                 Applicable Bonus Formula for the CEO and each
Entitled Employee, which may be for an individual or a group of Entitled
Employees.

4.03  Limitation of Bonuses and General Discretion

(a)                                  The Bonus for any Entitled Employee may
exceed or be below the amount calculated in accordance with this Section 4 as
determined by the Committee in their sole discretion.

(b)                                 An Entitled Employee who, whether voluntarily
or involuntarily, is terminated, demoted, transferred or otherwise ceases to be
an Entitled Employee at any time prior to the payment of Bonuses for any
Performance Period in accordance with Section 4.03 (Bonus Payments) shall not
be eligible to receive a partial or full Bonus award with respect to such
Performance Period, unless otherwise specifically determined by the Committee.

(c)                                  An Entitled Employee who was, during a year,
promoted to a position included in a Bonus Classification established by the
Committee, shall have his or her Bonus prorated in accordance with the period
of time he or she held such position.

(d)                                 An Entitled Employee who was, during a year,
promoted from one Bonus Classification to another Bonus Classification, shall
have his or her Bonus prorated in accordance with the period of time he or she
was in each Bonus Classification.

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(e)                                  Notwithstanding the Bonus Classifications
established by the Committee, the Committee may, designate an Eligible Employee
for inclusion in one of such Bonus Classifications when, but for such
designation, the Eligible Employee would not otherwise be included in such
Bonus Classification.

4.04  Bonus Payments

The Committee shall, within 60 days after the end of a Performance
Period, determine and approve in their sole and absolute discretion the amount
of Bonuses, if any, for each Entitled Employee for any given Performance
Period.  The Bonuses shall be paid to
Entitled Employees at the direction of the Committee, provided that such
payments shall be paid no later than 2-1/2 months after the end of the calendar
year in which such Bonuses are earned.

SECTION 5  — 
Administration of the Plan

5.01  Administration

The Committee (or its delegates) shall be responsible for the general
administration and interpretation of this Plan and for carrying out its
provisions, including the authority to construe and interpret the terms of this
Plan, determine the manner and time of payment of any Bonuses, prescribe forms
and procedures for purposes of Plan participation and distribution of Bonuses
and adopt rules, regulations and to take such action as it deems necessary or
desirable for the proper administration of this Plan.  The Committee (or its delegates) may employ
attorneys, consultants, accountants, agents, and other individuals, any of whom
may be an employee, and the Committee, the Corporation, and its officers and
directors shall be entitled to rely upon the advice, opinions, or valuations of
any such individuals. All actions taken and all interpretations and
determinations made by the Committee shall be made in the Committee’s sole
discretion and shall be final and binding upon the participants, the
Corporation, and all other interested individuals. To the extent applicable,
the Plan shall be administered with respect to individuals subject to the laws of
the U.S. so as to avoid the application of penalties pursuant to Section 409A
of the Internal Revenue Code.

5.02  Right to
Receive Payment

This Plan does not constitute a promise to pay and nothing in this Plan
shall be construed to create a trust or to establish or evidence any Entitled
Employees’ claim of any right to payment of a Bonus. Each Bonus under this Plan
shall be paid solely from general assets of the Corporation.  This Plan is unfunded and unsecured.

SECTION 6  — 
Provisions

6.01  Amendment or Termination

Subject to Section 6.02 (Effect of Amendment or Termination), this Plan
may be amended in whole or in part from time to time or terminated by the
Corporation.  Any amendment or
termination shall be binding on the Corporation, Entitled Employees, Eligible
Employees and their respective beneficiaries.

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6.02  Effect of Amendment or Termination

Notwithstanding Section 6.01 (Amendment or Termination), no amendment
or termination of any provision of this Plan shall directly or indirectly
deprive any Entitled Employee or beneficiary of all or any portion of a Bonus
payable with respect to any Performance Period ending prior to the date of the
amendment or termination.

6.03  No Enlargement of Contractual Rights

This Plan shall not give any Entitled Employee or Eligible Employee the
right to be retained in the service of the Corporation nor shall it interfere
with the right of the Corporation to terminate the employment of the Entitled
Employee or Eligible Employee. 
Participation in this Plan shall not give any Entitled Employee or
Eligible Employee any right or claim to any benefit, except to the extent
provided in this Plan.

6.04  Interpretation

This Plan shall be interpreted pursuant to the laws of the State of
Connecticut.  Section headings are for convenience
only and shall not be considered provisions of the Plan.  Words in the singular shall include the
plural, and vice versa, unless qualified by the context.

6.05  Withholding of Taxes

The Corporation shall withhold all applicable taxes from any amounts
paid pursuant to this Plan.

6.06  Binding on Successors

This Plan shall be binding on any successor or successors of
priceline.com Incorporated whether by merger, consolidation or otherwise.

6.07  Currency

The benefits payable pursuant to this Plan shall be paid in the same
currency as the Entitled Employee receives his or her regular wages or salary.

 5

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