Exhibit 10.16

                           PURCHASE AND SALE AGREEMENT


         THIS PURCHASE AND SALE AGREEMENT (the  "Agreement")  dated this 1st day
of December, 2000 is made and entered into between Sierra Health Services, Inc.,
a Nevada corporation  ("Sierra"),  Health Plan of Nevada,  Inc. ("HPN"),  Sierra
Health and Life Insurance Company, Inc. ("Sierra Health"), 2716 North Tenaya Way
Limited Partnership ("Tenaya  Partnership" and together with Sierra, HPN, Sierra
Health,  "Sellers"),  and CB Richard Ellis Corporate  Partners,  LLC, a Delaware
limited liability company ("Buyer").

         A.       Sellers own certain real property described in Exhibit 1
attached hereto.

         B. This Agreement  provides for the sale by Sellers and the purchase by
Buyer of the real property  identified  in Paragraph A above.  Buyer and Sellers
further  agree  that  concurrently  with  such  sale  Sellers,  or  wholly-owned
subsidiaries of Sierra, as the case may be, shall leaseback such properties from
Buyer.

         NOW,  THEREFORE,  for and in  consideration of the mutual covenants and
agreements hereinafter set forth, the parties agree as follows:

                                    ARTICLE 1
                                  Defined Terms



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1.1      Definitions.   As used herein, the following terms shall have the
meanings given:
         ------------

         "Appraisal" shall have the meaning given in Section 5.1.

         "Business Day" means a calendar day on which banks in Las Vegas, Nevada
shall be open to transact business.

         "Buyer's Conditions  Precedent" shall have the meaning given in Section
8.1.

         "Close of Escrow" means the date on which the Deeds are recorded.

         "Closing Date" means the date on which the Close of Escrow occurs.

         "Cure Period" shall have the meaning given in Section 4.3.

         "Deposit" shall have the meaning given in Section 3.1(a).

         "Due Diligence  Period" shall mean the period ending  December 8, 2000.
Provided,  however,  the  Due  Diligence  Period  may be  extended  for up to 10
business  days from  Buyer's  receipt of the items set forth in  Subsection  5.1
provided  that such  extension  does not extend  beyond  December  18, 2000 (the
"Extended Review Period").

         "Engineering Report" shall have the meaning given in Section 5.1.

         "Environmental Report" shall have the meaning given in Section 5.1.

         "Escrow"   means  the  escrow   opened  with  Escrow   Holder  for  the
consummation of the transaction described in this Agreement.

         "Escrow Holder" means Land America Title Insurance Company, National
Accounts, Los Angeles.

         "Governmental Regulations" means any laws, statutes,  ordinances, rules
and  regulations  (including,  without  limitation,  those relating to land use,
subdivision,  zoning,  environmental,  toxic or  hazardous  waste,  occupational
health and safety, earthquake hazard reduction,  building and fire codes) of any
governmental authority bearing on the construction, maintenance, use, operation,
management or ownership of the Properties.

         "Hazardous   Materials"   means  and  includes   petroleum,   asbestos,
polychlorinated  biphenyls,  urea  formaldehyde,  and any flammable  explosives,
radioactive  materials or hazardous,  toxic or dangerous  wastes,  substances or
related materials or any other chemicals,  materials or substances,  exposure to
which is  prohibited,  limited  or  regulated  by any  federal,  state,  county,
regional or local authority,  including,  but not limited to, substances defined
as such in (or  for  purposes  of)  the  Comprehensive  Environmental  Response,
Compensation,  and Liability  Act, as amended (42 U.S.C.  Section 9601, et seq.;
the Hazardous Materials Transportation Act (49 U.S.C. Section 1801, et seq); the
Resource  Conservation  and Recovery Act (42 U.S.C.  Section 6901, et seq.); and
any so-called  "Superfund"  or "Superlien"  law, or any other federal,  state or
local  statute,  law,  ordinance,  code,  rule,  regulation,   order  or  decree
regulating, relating to or imposing liability or standards of conduct concerning
any hazardous, toxic or dangerous waste, substance or material.

         "Improvements" means those certain buildings, installations, paving and
landscaping  presently  situated  on each  parcel  of  Land,  but not  including
Sellers' and Tenants' furniture and office equipment, except that as to the Land
located  at  2716  North  Tenaya,  "Improvements"  shall  include  the  Personal
Property.

         "Intangibles"   shall  mean  both  of  the   following  to  the  extent
assignable:  (a) the Licenses  and Permits and (b) all  building  names (if any)
used or  useful in  connection  with  each  parcel of Land and the  Improvements
thereon,  but only to the extent that the same are not trademarks or trade names
of the  Sellers  or their  affiliated  companies,  together  with  the  Sellers'
interest (if any) in and to any service and maintenance  contracts,  guarantees,
books, records, studies, audits, appraisals,  plans and specifications,  surveys
and warranties relating to each parcel of Land and the Improvements thereon.

         "Land" means those certain parcels of land more particularly  described
in Exhibit 1 attached hereto, together with all right, title and interest of the
Sellers in and to all  streets,  alleys,  easements  and  rights-of-way  in, on,
across, in front of, abutting or adjoining said land.

         "Lease"  refers to a bond net lease  covering a Property  as more fully
described in Section 2.2.

         "Lease Guaranty"  refers to an  unconditional  guaranty of the Tenant's
performance of its obligations  under a Lease as more fully described in Section
2.2.2.

         "Lender" refers to the entity making the Loan to Buyer.

         "Lender's  Title  Policy"  shall have the  meaning set forth in Section
8.1(a).

         "Licenses  and  Permits"  means  all  licenses,  permits,  certificates
(including,   without   limitation,   certificates   of   occupancy),   reports,
authorizations and approvals issued or granted by any governmental  authority in
connection with each parcel of Land and the Improvements thereon.

         "Loan" shall have the meaning given in Section 8.1(c).

         "Material Adverse  Condition" shall mean an environmental or structural
condition affecting any Property,  the remediation of which would cost in excess
of five percent (5%) of the  allocated  price for such  Property as set forth on
Exhibit 5.

         "Memorandum  of  Lease"  refers  to a  customary,  recordable  form  of
memorandum  of lease setting forth a  description  of the leased  premises,  the
parties and the term of the Lease.

         "Opening of Escrow"  means the date on which a fully  executed  copy of
this Agreement is delivered to Escrow Holder by Buyer and Sellers.

         "Opinion  of  Sellers'  Counsel"  means an opinion  letter  executed by
counsel for Sellers and Tenants that the Deeds,  Bills of Sale,  this Agreement,
the Leases,  Lease Guaranties and Subordination,  Non-Disturbance and Attornment
Agreements  have been duly executed by Sellers (or Tenants,  if applicable)  and
are  enforceable  in  accordance  with  their  terms  subject  to the  effect of
bankruptcy, insolvency,  reorganization,  anti-deficiency and other similar laws
now  or  hereafter  in  effect  relating  to or  affecting  the  enforcement  of
creditors' rights generally.

         "Other  Contract"  refers to the  Purchase and Sale  Agreement  between
Buyer and the owners of the Other Properties.

         "Other Properties" are listed on Exhibit 2 attached hereto.


         "Owner's Title Policy" shall have the meaning given in Section 8.1(a).

         "Permitted  Exceptions" as to a Property  means those Title  Exceptions
set forth in the  applicable  Title  Commitment  or reflected in the  applicable
Survey,  and any other  exceptions  or  conditions  that  affect or may affect a
Sellers'  title to or use of such  Property,  that are  approved or deemed to be
approved by Buyer in accordance with Section 4.2 and Section 4.3.

         "Personal Property" refers to the portable personal property, including
without  limitation the desks,  chairs,  cabinetry,  audio and video  equipment,
screens  and  other  furniture,  located  in  the  President's  Auditorium,  the
Chairman's  Auditorium  and the cafeteria at the 2716 North Tenaya Way Property,
which Personal  Property shall be conveyed to Buyer as provided  herein.  At the
end of the 15th year of the Lease  covering the 2716 North Tenaya Way  Property,
so long as Tenant is not then in default under such Lease, the Personal Property
shall be reconveyed to Sellers. In no event shall Sellers be required to replace
any of the  Personal  Property,  but  Sellers  may,  in their sole and  absolute
discretion, repair and/or replace the Personal Property as reasonably necessary,
and any such replacement items shall be deemed Personal Property.

         "Property"  refers  to one of the  parcels  of Land  together  with the
Improvements thereon and the Intangibles related thereto. "Properties" refers to
all of the Land, Improvements and Intangibles.

         "Purchase Price" shall have meaning given in Section 3.1.

         "Sellers'  Certificate"  shall  have the  meaning  set forth in Section
10.2.1.

         "Sellers'  Conditions  Precedent"  shall have meaning  given in Section
8.2.

         "Subordination,  Non-Disturbance  and Attornment  Agreement" shall have
the meaning specified in Section 10.2.1(h).

         "Survey" shall have the meaning specified in Section 4.1.

         "Tenant" means the tenant under a lease.

         "Title Report" shall have the meaning given in Section 4.1.

         "Title  Company"  shall  mean Land  America  Title  Insurance  Company,
National Accounts, Los Angeles office.

         "Title  Exception" means any lien, deed of trust,  security,  interest,
encumbrance,  pledge, assignment, claim, charge, lease (surface, space, mineral,
or otherwise), condition, restriction, restrictive covenant, exception, easement
(temporary  or  permanent),  right-  of way,  encroachment,  overlap,  or  other
outstanding  claim,  interest,  estate,  or equity of any nature that  affects a
Property.

                                    ARTICLE 2
                               Purchase Leaseback

2.1      Purchase  Agreement.  Sellers  agree to sell and convey the  Properties
to Buyer and Buyer agrees to purchase the  Properties from Sellers, upon the
terms and conditions herein set forth.



2.2      Lease.

         2.2.1 Bond Net Lease.  For each Property being sold to Buyer hereunder,
Buyer and each Tenant, as applicable, agree to execute a separate bond net lease
(individually,  a "Lease",  collectively,  the "Leases") under which such Tenant
will leaseback such Property from Buyer.  Each Lease shall commence on the Close
of Escrow and shall have a primary term of 15 years each. Tenant shall have five
5-year renewal  options.  Rent shall be payable  monthly in advance.  The annual
base rent for the primary  term of each Lease is set forth on Exhibit 3 attached
hereto.  The annual base rent for the 16th year of the Lease term shall be equal
to the greater of (a) 101.5% of the annual base rent for the preceding  year and
(b) the fair market rent for such  Property as of the  commencement  of the 16th
year of the Lease term.  The annual base rent for the 17th through the 40th year
of the Lease term shall be adjusted upward 101.5% annually.

                  Tenant's  obligation under each Lease to pay taxes,  insurance
premiums,   utilities,   environmental  costs  and  otherwise  to  maintain  the
applicable  Property  during  the  term  of  the  Lease  will  be  absolute  and
unconditional.  The Lease shall not permit  abatement  or  cessation  of rent or
lease  termination  by Tenant  during the lease term for any  reason,  including
casualty  loss.  Following a casualty loss,  Tenant shall  promptly  restore the
Property. Each Lease shall be cross-defaulted with every other Lease (as well as
the leases covering the Other  Properties)  except that in the event of a resale
of  one  or  more   Properties  or  Other   Properties,   each  Lease  shall  be
cross-defaulted  only with Leases covering Properties and Other Properties owned
by the same entity or its affiliate.

                  2.2.2  Lease  Guaranty.  Sierra  and  Buyer  shall  reasonably
cooperate  in  good  faith  to  designate  either  Sierra  or one or more of its
subsidiaries to be Tenants under one or more of the Leases. Sierra shall execute
and  deliver  to  Escrow  Holder  before  the  Closing  Date  a  Lease  Guaranty
unconditionally  guaranteeing Tenant's performance of its obligations under each
Lease in which Sierra is not the Tenant.

                  2.2.3   Form  of  Lease  and  Lease   Guaranty.   As  soon  as
practicable,  the parties  shall  negotiate  a form of Lease and Lease  Guaranty
consistent  with the  provisions  of this  Section 2.2. In the event the parties
have not  negotiated a mutually  acceptable  form of Lease and Lease Guaranty by
December 8, 2000,  either Sellers or Buyer may elect to terminate this Agreement
by  written  notice to the other  party(ies)  and to Escrow  Holder.  In such an
event, (a) Sellers shall reimburse Buyer for one half of all Loan fees forfeited
by Buyer as a result of the  termination  of this  transaction,  which Loan fees
(including  those under the Other  Contract) are expected to total  $175,000 and
(b) except as set forth in the preceding  subsection (a) and in Sections 5.2 and
10.1, neither party shall have any further rights or obligations hereunder.

         2.2.4 Letter of Credit/Deposit A. Prior to Close of Escrow, the Tenants
shall provide an  irrevocable  standby letter of credit (the "Letter of Credit")
or security  deposit  ("Security  Deposit  A") in the amount of $5.6  million in
favor of Landlord, but which Landlord may assign to Lender. The Letter of Credit
shall  be  issued  by a  financial  institution,  and be in a  form,  reasonably
acceptable  to Lender.  The Letter of Credit and  Deposit A may be drawn only in
the event of Tenant's monetary  default,  Tenant insolvency or Lease termination
due to Tenant  default  under a Lease.  The  Letter  of  Credit  may be drawn by
Landlord (or Lender as assignee) as follows:

                  (a) If there have occurred four rental  defaults,  one month's
rent under the Leases will be drawn.

                  (b)      If there have occurred four rental defaults, at least
                           two of which have occurred during the previous twelve
                           (12) months,  the full amount of the Letter of Credit
                           will be drawn.

                  (c) If there have  occurred  five  rental  defaults,  the full
amount of the Letter of Credit will be drawn.

         (d) If a Lease is  terminated  due to a Tenant  default  or if a Tenant
insolvency  occurs,  the full  amount of the  Letter  of  Credit  will be drawn.
"Tenant  insolvency"  means the filing by a Tenant or Sierra of any  petition to
take advantage of any state or federal  bankruptcy law,  insolvency law or other
law for the  protection  of debtors  or if any such  petition  is filed  against
Tenant or Sierra with its  consent or  acquiescence  or if any such  petition is
filed against the Tenant or Sierra  without its consent or  acquiescence  and is
not dismissed within 45 days.

         The  amount  of  the  Letter  of  Credit  (or  Security  Deposit  A  if
applicable)  will be reduced as  follows:  (a) upon the  partial  release of any
collateral  for the Loan and  payment  of the  specified  release  price for the
released asset, the Letter of Credit will be reduced, pro rata, in proportion to
the amount of the Loan that is repaid and (b) the amount of the Letter of Credit
will be reduced, pro rata, in proportion to the amount of principal amortization
that has been paid on the Loan.  The Letter of Credit (or Security  Deposit A if
applicable) will be released upon the first to occur of the following:

                  (a)      The loan to value ratio (without  taking into account
                           the value of the  Letter of Credit and based upon the
                           approved  appraised  values of the  Properties  as of
                           closing)   is  reduced  to  65%  as  a  result  of  a
                           prepayment  of  the  Loan,  the  partial  release  of
                           collateral and/or scheduled amortization of the Loan;

                  (b)      Sierra achieves a BBB rating or better from Fitch; or

                  (c)      The Loan is repaid in full.

         2.2.5  Security  Deposit  B. Prior to Close of  Escrow,  Tenants  shall
provide a cash Security Deposit  ("Security Deposit B") in the amount of 60 days
rent under the Leases. Security Deposit B shall be held in escrow in an interest
bearing  account for the  benefit of the  Landlord  under the  Leases.  Security
Deposit B and any accrued interest may be drawn by Landlord (upon written notice
to escrow and Tenant) under the same circumstances outlined above for the Letter
of Credit.  In the event of such a draw down,  Tenant shall be in default  under
the Lease until Security  Deposit B is replenished.  Security  Deposit B and any
accrued  interest  thereunder will be released to Tenant upon Sierra achieving a
BBB rating by Fitch or upon payoff of the Loan.  Upon sale of the 2716 N. Tenaya
Way Property,  Security Deposit B shall be reduced pro rata with the pay down of
the Loan.



                                    ARTICLE 3
                                 Purchase Price



<PAGE>




3.1 Purchase  Price.  The total purchase price for the Properties (the "Purchase
Price") and the allocation of the Purchase Price among each of the Properties is
set forth on Exhibit 5 attached  hereto.  Buyer shall pay the Purchase  Price to
Sellers as follows:

         (a) Within one  Business  Day  following  the Opening of Escrow,  Buyer
shall  deposit  in  Escrow  with  Escrow  Holder an  earnest  money  deposit  in
immediately available funds in the amount of $125,000. These funds together with
any additional  deposit made by Buyer  pursuant to Section 5.3.2  (collectively,
the  "Deposit")  shall be held by Escrow Holder in an interest  bearing  account
insured by the federal  government  in an  institution  as directed by Buyer and
reasonably  acceptable  to  Sellers.  If the  transaction  contemplated  by this
Agreement  is  consummated  as  contemplated  hereunder,  the  Deposit  plus all
interest  accrued  thereon  shall be paid to Sellers  and  credited  against the
Purchase  Price.  If the  transaction  contemplated  by  this  Agreement  is not
consummated  because of the failure of any Buyer's  Condition  Precedent  or any
other  reason  except for a default  under this  Agreement on the part of Buyer,
Buyer shall  immediately  recover the Deposit plus all interest accrued thereon.
If the transaction  contemplated by this Agreement is not consummated because of
a default  under  this  Agreement  on the part of Buyer,  the  Deposit  plus all
interest  accrued  thereon shall be paid to and retained by Sellers  pursuant to
Section 13.1 below.

         (b) The proceeds of the Loan (as described in Section  8.1(c)) shall be
deposited  into Escrow in immediately  available  funds on or before the Closing
Date.

         (c) Buyer shall pay the balance of the Purchase  Price to Escrow Holder
by wire transfer of immediately  available  funds on or before the Closing Date,
net of all prorations or adjustments as provided herein.

         (d) The funds deposited into Escrow pursuant to Section 3.1(a), (b) and
(c) shall be disbursed to Sellers (by wire  transfer) as directed by Sellers and
in accordance with the provisions of Section 10.4.2.

                                    ARTICLE 4
                                Title and Survey

 4.1 Title Documents and Survey. Sellers, at their expense, have furnished Buyer
with preliminary title reports (collectively, the "Title Reports", individually,
a "Title  Report")  issued by Nevada Title Company for each  Property,  together
with copies of all  documents  referred to in the Title  Reports.  Nevada  Title
shall share equally in the title  premiums and escrow fees,  but shall not issue
the Title Policies. Sellers have also furnished one print to Buyer and one print
to the  Title  Company  of an ALTA  survey  of each  Property  (individually,  a
"Survey", collectively, the "Surveys").

 4.2 Buyer's Approvals. Buyer's obligations under this Agreement are conditioned
on Buyer's  approval of the Surveys and status of title to each Property.  Buyer
shall have until  December 11, 2000 in which to review all matters  reflected in
those documents. If Buyer has not notified Sellers in writing of its disapproval
of such matters within such period, it shall be deemed to have approved them.

 4.3 Sellers' Option to Cure. If Buyer timely notifies Sellers in writing of its
disapproval  of any of the title or survey items  furnished to Buyer pursuant to
Section  4.1,  then  Sellers  shall,  within 10 days after  Sellers'  receipt of
Buyer's notice (such 10 day period referred to herein as the "Cure Period") have
the option to satisfy,  correct or remove any such title or survey items, obtain
title insurance coverage therefor,  or provide assurance that such items will be
otherwise  satisfied,  corrected or removed by the Close of Escrow,  at Sellers'
expense and to Buyer's and Lender's reasonable satisfaction. If, within the Cure
Period,  Sellers are unable or elect not to eliminate  any such item, or provide
adequate  assurance that it will be eliminated as of the Close of Escrow,  Buyer
shall  have the right to either  (a) waive its  disapproval  of such item or (b)
terminate  this  Agreement.  Any  items not  objected  to by Buyer and any items
waived by Buyer shall be deemed Permitted Exceptions.

                                    ARTICLE 5
                              Due Diligence Period

 5.1 Sellers' Delivery of Specified Documents.  Sellers, at their expense, shall
provide  to or make  available  for  inspection  by  Buyer  or  Buyer's  agents,
representatives  or  designees,  all of the  following  as they  pertain  to the
Properties,  to the extent the same have not been  previously  provided  or made
available:

         (a)      The latest property tax bills and assessor's statements of
current assessed value;

         (b) Within one  Business  Day after  being  notified  of the name of an
environmental  consultant acceptable to Lender, Seller and Buyer shall order, or
approve  Lender's  order  of, a current  "Phase  One"  environmental  assessment
("Environmental   Report")  of  each  Property  meeting  Lender's  requirements,
conducted  using  ASTM  standards  by an  independent  environmental  consultant
registered  with the Lender and  approved by Buyer,  which  assessment  shall be
certified to Buyer and Lender;

         (c) "As-built" plans and  specifications of the Improvements  including
the actual floor area measurements, CAD floor diagrams, detailed gross, rentable
and  usable  floor  area  calculations  for each  building,  each floor and each
subtenant  (if any),  to the extent the same are in the  possession,  custody or
control of Sellers or their agents.

         (d)      Any soils  reports  and  geological  studies,  to the  extent
the same are in the  possession,  custody or control of
Sellers or their agents;

         (e)      Any  covenants,  conditions  and  restrictions,  or easements,
of which Seller has knowledge and which have not been provided to Buyer by the
Title Company;

         (f) Any written  notices,  reports,  citations,  orders,  or  decisions
relating to the Properties from any governmental authorities,  to the extent the
same are in the possession, custody or control of Sellers or their agents;

         (g) Copies of all documents  relating to the presence or absence of any
endangered species,  environmentally sensitive areas or environmental conditions
on the  Properties,  to the  extent the same are in the  possession,  custody or
control of Sellers or their agents;

         (h)      True and correct copies of all Licenses and Permits;

         (i) Within one  Business  Day after  being  notified  of the name of an
appraiser  acceptable  to  Lender,  Seller  and Buyer  shall  order,  or approve
Lender's order of, an MAI appraisal (the "Appraisal") of each Property performed
by an appraiser  approved by, and certified to, Buyer and Lender,  setting forth
the fair market value of the Property;

         (j) Within one  Business  Day after  being  notified  of the name of an
engineering firm acceptable to Lender,  Seller and Buyer shall order, or approve
Lender's order of, a written  structural  engineering report together with a PML
seismic  study  (collectively,  "Engineering  Report") as to each Property by an
engineering firm approved by, and certified to, Buyer and Lender;

         (k)  Subtenant  estoppel  certificates  and  copies of any  leases  and
subleases in form  acceptable to Buyer and Lender as to any  subtenants not on a
month-to-month  sublease,  rent rolls and an aged receivable  report relating to
sublease income;

     (l) A statement,  certified by the  applicable  Seller,  itemizing the real
estate  operating  expenses  (taxes,  utilities,  maintenance,  etc.) and rental
income  for the last two  years  and for the most  recent  quarter,  in the form
customarily prepared by Sellers;

     (m) Statements of insurance coverage and premiums by policy type and copies
of insurance policies;



<PAGE>




         (n)      The most recent title report, including copies of all listed
exceptions;

         (o)      Access to all warranty  agreements and copies of those
warranty agreements covering property with an original cost of
greater than $10,000;

         (p) Access to all operating,  management and maintenance contracts,  if
any, and any amendments and letter agreements relating thereto and a list of all
such agreements  setting forth the name of the vendor,  the service provided and
the vendor's monthly (or yearly) fee;

         (q)      A list of Personal Property to be conveyed.

5.2  Right of  Access  and  Investigation.  Before  the  Close of  Escrow,  upon
reasonable  notice to Sellers and upon  Sellers'  consent,  Buyer shall have the
right to conduct any  investigations of the Properties as it desires,  including
without  limitation,  soils conditions,  engineering,  and accessibility.  Buyer
shall conduct all such investigations in a manner that shall minimize disruption
of  the  businesses  being  conducted  on  the  subject  Property.  Buyer  shall
indemnify,  defend,  and hold Sellers,  Tenants and their employees and business
invitees  harmless  from all  liabilities  and  expenses  (including  reasonable
attorneys' fees, but excluding any  consequential or special damages)  resulting
directly from Buyer's investigations of the Properties.  Provided, however, that
any  third-party  consultants or experts  selected by Buyer shall be required to
provide evidence of liability  insurance in amounts and with coverage  customary
in the industry,  and reasonably  acceptable to Sellers.  This  indemnity  shall
survive the Close of Escrow and the termination of this Agreement. Buyer further
agrees that  Sellers,  Tenants and their  employees  and  business  invitees are
released  from any and all  liability  relating to any claim for injury,  death,
sickness or property damage arising from or in connection with  investigation of
the Properties by Buyer, its managers,  officers,  employees and affiliates,  or
others acting for the benefit of Buyer.

5.3      Buyer's Termination or Acceptance of Due Diligence.

         5.3.1 At any time prior to December 8, 2000,  Buyer may in its sole and
absolute discretion  terminate this Agreement if Buyer is not satisfied with its
review of the matters  specified  in Section  5.1, or for any other  reason,  by
giving  Sellers  written notice of  termination.  Provided,  however,  that with
respect to items set forth in Section 5.1, the written notice of termination may
be sent during the  Extended  Review  Period,  but only in  accordance  with the
provisions of Section 5.3.2. If Buyer timely  terminates  this Agreement,  Buyer
shall immediately recover the Deposit plus all interest accrued thereon.

         5.3.2 If Buyer does not terminate  this  Agreement  pursuant to Section
5.3.1, then:

                  (a)  Within  one  Business  Day  after  expiration  of the Due
Diligence  Period,  Buyer shall wire transfer an  additional  $125,000 to Escrow
Holder which funds shall be part of the Deposit;

                   (b) (i) If Buyer has learned of a Material Adverse  Condition
affecting any Property other than the 2716 North Tenaya Way Property, then Buyer
may terminate this Agreement as to the affected Property or Properties by giving
the applicable  Seller during the Due Diligence  Period,  or the Extended Review
Period, if applicable,  a written notice of termination  specifying the Material
Adverse  Condition or Conditions and the affected  Properties.  However,  if the
Material Adverse Condition is correctable, this Agreement shall remain in effect
as to the affected  Property  provided  that within three  Business Days of such
notice,  the applicable  Seller gives Buyer and Escrow Holder a Notice of Intent
to Correct  Material  Adverse  Condition.  The term "Notice of Intent to Correct
Material Adverse  Condition" refers to a written notice signed by the applicable
Seller reflecting  Seller's intent to correct the Material Adverse Condition and
instructing  Escrow Holder that unless Seller has corrected the Material Adverse
Condition  before  Close of  Escrow,  Buyer  shall  receive a credit at Close of
Escrow for an amount equal to the cost of correction  (as  determined by Lender)
which  amount  shall be  retained  by  Lender  and  disbursed  to  Seller  after
correction of the Material Adverse Condition.  If the applicable Seller fails to
give timely Notice of Intent to Correct  Material Adverse  Condition,  then this
Agreement  shall be terminated as to the affected  Property or  Properties,  the
parties shall proceed with the sale of the remaining Properties and the Purchase
Price shall be reduced by the amount  allocated to the applicable  Properties in
Exhibit 5;

     (ii) If Buyer learns of a Material  Adverse  Condition  affecting  the 2716
North Tenaya Way Property, then Buyer may terminate this Agreement by giving the
2716 North Tenaya Way Seller  during the Due Diligence  Period,  or the Extended
Review  Period,  if applicable,  a written notice of termination  specifying the
Materially Adverse Condition or Conditions and the affected  Property.  However,
if the Material Adverse Condition is correctable, this Agreement shall remain in
effect  provided that within three Business Days of such notice,  the 2716 North
Tenaya Way Seller  gives  Buyer and Escrow  Holder a Notice of Intent to Correct
Material  Adverse  Condition.  If the 2716 North Tenaya Way Seller fails to give
timely  Notice  of Intent  to  Correct  Material  Adverse  Condition,  then this
Agreement  shall  terminate as to all Properties in which case Sellers shall pay
Lender's out of pocket  costs that Buyer would  otherwise be obligated to pay in
an amount not to exceed $75,000; and


                  (c) The only remaining  contingencies to Buyer's obligation to
consummate the transaction  contemplated herein (as to any Properties  remaining
after application of this Section 5.3.2) shall be Buyer's  Conditions  Precedent
as set forth in Section 8.1 below.


                                    ARTICLE 6
              Representations, Warranties, and Covenants of Sellers

6.1 Representations and Warranties of Sellers.  Sellers represent and warrant to
Buyer as provided below in this Article 6. The representations and warranties of
Sellers  contained in this  Agreement are made as of the date of this  Agreement
and as of the Close of Escrow and shall survive the Close of Escrow for a period
of one year.  For  purposes  of this  Section  6.1,  the term  "Sellers'  actual
knowledge" shall mean the actual knowledge of the following  officers of Sellers
after due inquiry by each: Dr. Anthony Marlon,  William Godfrey, Paul Palmer and
Frank Collins.

         (a)  There  are no  adverse  or  other  parties  in  possession  of the
Properties other than as shown in the inter-company occupancy agreements amongst
Sellers' affiliated  entities,  leases or subleases provided and/or disclosed to
Buyer pursuant to this Agreement.

         (b) Each of the Sellers, as applicable,  owns and shall convey to Buyer
fee  simple  title to each  respective  Property,  free and clear of all  liens,
encumbrances, charges, easements, interests or other rights, subject only to the
Permitted Exceptions approved by Buyer pursuant to this Agreement.

         (c)  Sellers  have the full right,  power,  and  authority  to sell and
convey  their  respective  interests  in the  Properties  as  provided  in  this
Agreement and to carry out Sellers' respective  obligations  hereunder and under
any other documents and instruments executed by Sellers pursuant hereto, and all
requisite action necessary to authorize Sellers to enter into this Agreement and
to carry  out  Sellers'  respective  obligations  hereunder  and under any other
documents and instruments executed by Sellers pursuant hereto has been, or on or
before the Closing Date, will have been, taken.

         (d) All of the  individuals  executing  this  Agreement  and any  other
documents and  instruments  executed by Sellers  pursuant  hereto have the legal
power,  right, and actual  authority to bind the respective  Seller to the terms
and conditions hereof and thereof.

         (e) This  Agreement  is,  and the  Leases,  the  Lease  Guaranties  (if
applicable)  and all  documents  required  hereby to be  executed by Sellers (or
Tenants) shall be, valid, legally binding obligations of and enforceable against
Sellers (or Tenants if applicable) in accordance with their terms,  subject only
to applicable bankruptcy, insolvency, reorganization, moratorium laws or similar
laws or equitable  principles  affecting  or limiting the rights of  contracting
parties generally.

     (f) Sellers and Tenants are in good standing in the State of Nevada and are
authorized to do business in the State of Nevada.

         (g) Sellers  have not  received  written  notice from any  governmental
authority  requiring Sellers to correct any condition with respect to all or any
portion of any Property by reason of a violation of any Governmental  Regulation
which has not been  corrected;  and Sellers have not received  written notice of
any  pending  condemnation  action  with  respect  to all or any  portion of any
Property.  As of the Closing  Date,  the  Properties  will comply fully with all
Governmental Regulations.

         (h) To the best of  Sellers'  actual  knowledge,  there are no  pending
claims,  suits,   actions,  or  arbitrations  or  regulatory,   legal  or  other
proceedings or investigations which affect the Properties or Sellers' rights and
obligations under this Agreement.

         (i) To the best of Sellers' actual knowledge,  each Property has access
to public streets and utilities necessary for the operation of the Property.

         (j) To the best of Sellers'  actual  knowledge,  except as shown on the
Surveys,  there are no  encroachments  on the Land nor any  encroachments by the
Improvements onto any easements, streets or adjoining property.

         (k) Sellers have not received  notice of, and have no actual  knowledge
or information of, any pending change in any Governmental Regulations applicable
to any  Property  which  would  result in any  material  change in any  physical
condition of any Property or in any way limit or impede in any material  respect
the intended operations of any Property.

         (l) The  execution and delivery of this  Agreement,  the Leases and the
Lease  Guaranties  (if   applicable),   the  consummation  of  the  transactions
contemplated  in this Agreement and in the Leases,  and the compliance  with the
terms of this  Agreement,  the Leases and the Lease  Guaranties (if  applicable)
will not conflict with or result in a violation of any  applicable  Governmental
Regulations or any judgment,  order, or decree of any court having  jurisdiction
over any Seller or any Property.

         (m) None of the  Sellers is a "foreign  person" as that term is defined
in Section  1445 of the  Internal  Revenue  Code of 1986,  as  amended,  and any
applicable regulations promulgated thereunder.

         (n) As of the  Closing  Date,  there  will  not be any  new  agreements
entered  into by  Sellers  or  their  respective  predecessors-in-interest  with
respect  to any  Property  which  would  create  a lien  or  encumbrance  on any
Property,  and Buyer  will not be  subject  to any  liabilities  or  obligations
arising from any such agreements. Provided, however, that in the event of a lien
or non-consensual encumbrance, Sellers shall not be in default of this provision
if they shall cause the same to be insured over by title insurance,  or released
of record by filing a security bond, in any such case, at Sellers' sole expense.

         (o) All  operations  or  activities  upon,  or use or  occupancy of the
Properties by Sellers,  or to the best of Sellers' actual knowledge by any prior
or current owner, tenant or occupant of the Properties, has been in all material
respects in compliance with all Governmental Regulations governing or in any way
relating to the generation,  handling,  manufacturing,  treatment, storage, use,
transportation,  spillage,  leakage,  dumping,  discharge  or disposal  (whether
accidental or intentional) of Hazardous  Materials,  and neither Sellers, nor to
the best of Sellers' actual  knowledge any prior or current tenant,  occupant or
prior  owner  of the  Properties,  has  engaged  in or  permitted  any  dumping,
discharge,  disposal,  spillage or leakage (whether legal or illegal, accidental
or intentional) of such Hazardous  Materials,  at, on, in or about any Property.
To the best of Sellers' actual knowledge,  and except as otherwise  disclosed to
Buyer  by  Sellers,  there  is not  present  upon any  Property,  any  Hazardous
Materials, or any structures,  fixtures, equipment or other objects or materials
containing  Hazardous  Materials in violation  of any  Governmental  Regulation.
Except as  otherwise  disclosed  to Buyer by Sellers,  there are no  underground
storage tanks present on any Property. To the best of Sellers' actual knowledge,
there is no proceeding or inquiry by any governmental  authority with respect to
the presence of Hazardous  Materials  on any Property or the  migration  thereof
from or to other property.

         (p) To the best of Sellers' actual  knowledge,  all documents or copies
thereof  delivered by Sellers to Buyer,  including those  delivered  pursuant to
Section 5.1 above are true,  complete  and accurate and have not been amended or
modified except as disclosed in writing to Buyer.

         (q)      Exhibit 1 accurately reflects the actual square footage of the
applicable Improvements.

         (r) As of the Close of Escrow, no Seller (including Sierra) shall be in
default under the terms of any of the loan  documents  relating to Sierra's line
of credit wherein Bank of America is acting as lead creditor("Credit Line").

         The  warranties in this Section 6.1 are subject to  exceptions  for the
matters (if any) referenced on the Disclosure List attached as Exhibit 6 to this
Agreement,  which  Disclosure  List may be  supplemented  by Sellers at any time
prior to Closing.  Provided,  however,  that should any such supplement reveal a
Material  Adverse  Condition not previously  disclosed or known by Buyer,  Buyer
shall  have the  right to  immediately  provide  Sellers  a  written  notice  of
termination as provided in Section 5.3.2(b).

         6.2 Additional  Covenants and Agreements of Sellers.  Sellers  covenant
and agree with Buyer that from the date of this Agreement until the Closing Date
or earlier  termination of this Agreement,  Sellers shall (i) materially  comply
with all Governmental  Regulations  affecting the Properties,  (ii) advise Buyer
promptly of any litigation, arbitration or administrative hearing concerning any
Property,  (iii) advise Buyer promptly of any material  damage to or destruction
of any Property, (iv) advise Buyer promptly after Sellers' discovery of any fact
or circumstance  which would make any of the warranties and  representations  of
Sellers herein contained  inaccurate in any material respect, (v) not enter into
any new occupancy  agreements,  leases or subleases (not cancellable on 30 days'
notice) relating to any Property,  without Buyer's prior written  consent,  that
will bind Buyer or affect any Property after the Close of Escrow,  (vi) maintain
the Properties in good  condition,  (vii) keep all existing  insurance  policies
affecting the Properties in full force and effect,  (viii) use due diligence and
its best efforts to keep in full force and effect  and/or renew all Licenses and
Permits, (ix) not convey all or any portion of any Property,  and, after the Due
Diligence Period,  Sellers will not, without the prior written consent of Buyer,
which consent will not be unreasonably withheld or delayed, subject any Property
to any  additional  liens,  encumbrances  (unless  Sellers bond around or insure
over), covenants,  conditions,  easements,  rights of way or similar matters (it
being  reasonable for Buyer to withhold  consent to any of the same if the value
of the Property would be affected thereby) (x) not make any material alterations
to any Property and (xi) provide Buyer with (A) a weekly  written  update of the
status of Sellers'  efforts to cure the  default  presently  existing  under the
Credit Line (B) 24 hour written  notice of any material  change in the status of
such efforts and (C) as soon as practicable,  written  evidence that the default
has been cured or will be cured upon consummation of this transaction.

                                    ARTICLE 7
                     Representations and Warranties of Buyer

     7.1  Buyer  represents  and  warrants  to  Sellers  as of the  date of this
Agreement and as of the Close of Escrow:

         (a) Buyer has the full right,  power,  and  authority  to purchase  the
Properties  from Sellers as provided in this  Agreement and to carry out Buyer's
obligations  hereunder and under any other documents and instruments executed by
Buyer pursuant hereto,  and all requisite action necessary to authorize Buyer to
enter into this  Agreement  and to carry out Buyer's  obligations  hereunder and
under any other documents and instruments  executed by Buyer pursuant hereto has
been, or on the Closing Date, will have been, taken;

         (b) All of the  individuals  executing  this  Agreement  and any  other
documents  and  instruments  executed  by Buyer  pursuant  hereto have the legal
power,  right,  and actual  authority to bind Buyer to the terms and  conditions
hereof and thereof.

                                    ARTICLE 8
            Conditions Precedent to Buyer's and Sellers' Performance

8.1  Conditions  to Buyer's  Obligation.  Buyer's  obligation  to  purchase  the
Properties  under this Agreement is subject to the  satisfaction  of each of the
following conditions ("Buyer's Conditions Precedent") any of which may be waived
in whole or in part only in writing by Buyer at or prior to the Closing Date:

         (a) The Title Company  shall be ready,  willing and able to issue as of
the  Close of  Escrow  (i)  ALTA  extended  coverage  owners  policies  of title
insurance  (including  mechanics'  lien coverage,  Form  B-1970)("Owner's  Title
Policies")  insuring fee  ownership of each Property in the name of Buyer or its
assignee  in the amount of the  Purchase  Price  allocated  to such  Property in
Exhibit 5, subject only to the  Permitted  Exceptions  and other items that have
been approved by Buyer pursuant hereto with  endorsements  confirming  that: (A)
each Property is as shown on the applicable Survey (CLTA endorsement 116.1), (B)
each Survey shows the correct location and dimensions of the applicable Property
(CLTA  endorsement  116), (C) each Property consists of one or more separate tax
parcels,  (D) each Property is one contiguous parcel (CLTA Form 116.4), (E) each
Property  is in  compliance  with all zoning laws (ALTA Form 3.1 and/or a zoning
letter from the appropriate  local land use agency,  as required by the Lender),
(F) each Property has road access (CLTA  Endorsement  103.7) and, (G) such other
endorsements as Buyer may reasonably  require and (ii) ALTA lender's policies of
title insurance  ("Lender's Title Policies") in the original principal amount of
the Loan with the endorsements  referred to in Subsections (i) (A)-(F) above and
the following endorsements:  (A) covering loss from an environmental  protection
lien  (ALTA  Form  8.1)  and  (B)  covering  losses  relating  to  restrictions,
encroachments  and  minerals  (ALTA  Form 9). The  Owner's  and  Lender's  Title
Policies  shall be  reinsured  in an  amount,  and by a  company  or  companies,
acceptable to both Buyer and Lender.

     (b) Sellers shall have  delivered to Escrow  Holder the items  described in
Section 10.2.1.

         (c) Buyer shall have obtained (and the proceeds thereof shall have been
deposited  into Escrow) a nonrecourse  loan (the "Loan") of not less than 75% of
the Purchase  Price  secured by first deeds of trust on each of the  Properties,
which Loan (i) shall be amortized on a 15 year  schedule and shall bear interest
at a rate not greater  than LIBOR plus 225 basis  points (ii) shall  require the
holder of the Loan  ("Lender")  to release a Property or  Properties  from liens
securing such Loan upon payment to Lender of an amount equal to 115% of the Loan
balance  allocated to such  Property or  Properties  (iii) shall not contain any
yield maintenance premiums,  bond deposit requirements,  lockouts or any similar
limitations  upon, or penalties for, Loan  prepayment and (iv) shall have a term
of one year (plus such  extensions  as are set forth in the  current  Fleet Bank
term sheet).  Buyer agrees to keep Sellers reasonably  apprised of the status of
the Loan and shall  within one (1)  business  day after  receipt of notice  from
Lender that one or more of the  Properties  will not be  financed,  send Sellers
notice thereof.

         (d)  There   shall  be  no   material   breach   of  any  of   Sellers'
representations,  warranties  or covenants  set forth in Sections 5.1, 5.2, 6.1,
and 6.2 as of the Close of Escrow.

         (e) Buyer shall not have  terminated  this Agreement in accordance with
Sections 4.3, 5.3, 11.1 or 11.2 as to the Properties to be sold.

         (f)  All  parties  shall  be  ready,  willing  and  able to  close  the
sale-leaseback described in, and in accordance with, the Other Contract.

8.2  Conditions  to  Sellers'  Obligation.   Sellers'  obligation  to  sell  the
Properties  under this Agreement is subject to the  satisfaction  of each of the
following  conditions  ("Sellers'  Conditions  Precedent")  any of which  may be
waived in whole or in part only in writing by Sellers at or prior to the Closing
Date:

     (a) There shall be no material breach of any of Buyer's representations and
warranties set forth in Article 7, as of the Close of Escrow.

     (b) Buyer shall have  delivered  to Escrow  Holder the items  described  in
Section 10.2.2.

         (c)  All  parties  shall  be  ready,  willing  and  able to  close  the
sale-leaseback described in, and in accordance with, the Other Contract.

8.3 Failure of Sellers' or Buyer's Conditions  Precedent.  If any of Sellers' or
Buyer's  Conditions  Precedent  are not  satisfied  or waived in  writing by the
applicable  party on or before the Closing Date,  this Agreement shall terminate
in accordance with Section 10.1, subject to the provisions of Article 13.

8.4 Termination of Escrow. Upon termination of this Escrow as to all Properties,
Escrow Holder shall promptly return to Sellers and Buyer any funds and documents
deposited  by them,  respectively,  into Escrow,  except as  otherwise  provided
herein.

                                    ARTICLE 9
                                Opening of Escrow

         Buyer  and  Sellers  shall,  within  one  business  day after the final
execution  of this  Agreement  by all  parties,  cause the  Opening of Escrow by
delivering a fully executed copy of this Agreement to Escrow Holder.  The Escrow
Holder is authorized  and instructed to act in accordance  with this  Agreement,
which shall constitute escrow  instructions for this transaction.  If the Escrow
Holder requires any additional instructions,  Buyer and Seller shall execute and
deliver to Escrow Holder any such  additional or  supplementary  instructions as
may be necessary or  convenient  to implement  the terms of this  Agreement  and
close  the  transaction   contemplated  hereby,   provided  that  they  are  not
inconsistent with the terms of this Agreement.

                                   ARTICLE 10
                                 Close of Escrow

10.1 Date and Place of Close of Escrow.  Escrow shall close after all conditions
have been satisfied or waived on a date mutually agreed upon by the parties that
is no later than  December  29,  2000.  If Escrow does not close by December 29,
2000, unless mutually  extended,  upon written demand of either party the Escrow
Holder shall return to each party who has complied  with all of its  obligations
under this Agreement, all funds and documents deposited in Escrow by such party.
In addition, Buyer shall use its best efforts in requesting Lender to release to
Seller,  or at Seller's option,  assign all due diligence  materials ordered and
processed  or  received,  including  but not limited to,  materials  and reports
obtained  pursuant  to Section  5.1(b),  (i) and (j), to parties  designated  by
Seller.  The Close of Escrow  shall  take place in the  offices of Nevada  Title
Company in Las Vegas,  Nevada or such other place as is mutually  acceptable  to
Buyer and Sellers,  although Buyer and Sellers need not be physically present at
the Close of Escrow.

10.2     Items to be Delivered at the Close of Escrow.

10.2.1 By Sellers.  Sellers  shall  deliver or cause to be  delivered  to Escrow
     Holder  on  or  prior  to  the  Closing  Date  the  -----------   following
     instruments and documents for the Properties:

                  (a)  Deeds.  A Grant,  Bargain,  Sale  Deed for each  Property
("Deed") duly executed and  acknowledged  in recordable  form by the appropriate
Seller, conveying the Property to Buyer.

     (b) Leases.  The Leases duly  executed by Tenants,  each  accompanied  by a
Memorandum of Lease, in recordable form. -------

     (c) Lease  Guaranties.  A Lease Guaranty duly executed by Sierra, as to any
Lease in which Sierra is not the Tenant.

(d)  Sellers' Certificate.  A certificate  ("Sellers'  Certificate") executed by
     Sellers providing that Sellers'  representations made in this Agreement are
     correct as of the Close of Escrow.

                  (e) Non-Foreign  Certification.  A certification duly executed
by each Seller ("FIRPTA  Certificate"),  setting forth such Seller's address and
federal tax  identification  number and certifying that such Seller is a "United
States Person" and that such Seller is not a "foreign person" in accordance with
Sections 7701 and 1445 of the Internal Revenue Code of 1986, as amended, and any
regulations promulgated thereunder.

                  (f) Proof of Authority.  Such proof of Sellers' (and Tenants')
authority and  authorization  to enter into this  Agreement and  consummate  the
transactions  contemplated  hereby, and such proof of the power and authority of
the  individual(s)  executing and/or  delivering any  instruments,  documents or
certificates  on behalf of Sellers (or  Tenants) to act for and bind Sellers (or
Tenants),  as applicable,  as may be reasonably required by the Title Company or
Buyer.

     (g)   Lien   Affidavits.   Any   lien   affidavits   or   mechanic's   lien
indemnifications as may be reasonably requested by the Title Company in order to
issue the Owner's and Lender's Title Policies.

                  (h) Subordination,  Non-Disturbance and Attornment Agreements.
Subordination,  Non-Disturbance and Attornment  Agreements,  in forms reasonably
acceptable to Lender and Sellers,  duly executed by Tenants,  subordinating  the
Leases to the deeds of trust securing repayment of the Loan.

     (i) Opinion of Sellers'  Counsel.  The original  duly  executed  Opinion of
Sellers'  Counsel in form and  substance  reasonably  satisfactory  to Buyer and
Lender.

                  (j) REA. A  Reciprocal  Easement  Agreement,  an  amendment to
existing  Reciprocal  Easement  Agreements,  or other  documentation in form and
substance reasonably  satisfactory to Buyer and Lender assuring adequate parking
to the Properties.

               (k) Letter of  Credit/Security  Deposits.  (A) Security Deposit B
          and (B) the Letter of Credit or Security Deposit

A.

                    (l)  Other  Documents.  Any other  documents or  instruments
                         required to consummate  the  transaction  in accordance
                         with this Agreement.

     10.2.2 By Buyer.  Buyer shall  deliver or cause to be  delivered  to Escrow
Holder on or prior to the Closing Date the following instruments and documents:

                  (a)      Purchase Price.  The Purchase Price and Buyer's share
 of closing costs.


                  (b)      Leases.  The Leases duly executed by Buyer, each
accompanied by a Memorandum of Lease in recordable form.
                           -------

                  (c) Proof of  Authority.  Such proof of Buyer's  authority and
authorization  to enter into this  Agreement  and  consummate  the  transactions
contemplated  hereby,  and  such  proof  of  the  power  and  authority  of  the
individual(s)   executing  and/or  delivering  any  instruments,   documents  or
certificates  on behalf of Buyer to act for and bind Buyer as may be  reasonably
required by the Title Company or Sellers.

(d)  Other Documents.  Any other documents or instruments required to consummate
     the transaction in accordance with this Agreement.

10.3 Cost of  Closing.  Sellers  shall pay the direct  cost of the  Owner's  and
Lender's  Title  Policies and all other charges of the Title  Company,  Surveys,
Environmental Reports, Appraisals,  Engineering Reports, 1/2 of all escrow fees,
all transfer  taxes payable on  recordation  of the Deeds and the deeds of trust
securing the Loan,  all recording  fees and all sales,  use and ad valorem taxes
connected  with Close of Escrow.  Buyer shall pay 1/2 of all escrow  fees.  Each
party shall bear the expense of its own counsel.  This Section shall survive the
Close of Escrow for all purposes.

     10.4  Disbursements  and Other  Actions by Escrow  Holder.  At the Close of
Escrow, Escrow Holder shall promptly:


         10.4.1 Recording.  With respect to each Property,  cause first the REA,
then the Deed,  then the deed of trust securing the Loan, then the Memorandum of
Lease, then the Subordination, Non-Disturbance and Attornment Agreement and then
any other documents which Buyer and Sellers may mutually direct,  to be recorded
in the  official  records  of the  county in which the  applicable  Property  is
located  and obtain  conformed  copies  thereof  for  distribution  to Buyer and
Sellers.

         10.4.2 Funds.  Promptly following  recordation of each of the documents
set forth in Section 10.4.1,  disburse all funds deposited with Escrow Holder by
Buyer as follows:

                  (a)      Deduct all items chargeable to the account of Sellers
 pursuant this Agreement.

                  (b)      Disburse  the  expenses  payable by Buyer and Sellers
  pursuant to this  Agreement  to the parties  entitled
thereto.

                  (c)      Disburse the balance of the Purchase Price to
Sellers.

                  (d)      Disburse the remaining balance of the funds, if any,
to Buyer.

         10.4.3   Title  Policies.  Direct the Title  Company to issue the
Owner's  Title  Policies  to Buyer and the  Lender's  Title Policies to Lender.

         10.4.4  Delivery of Documents  to Buyer.  Deliver to Buyer the Sellers'
Certificate and Opinion of Sellers'  Counsel,  one executed  counterpart copy of
each Lease, the FIRPTA Certificate,  and any other documents (or copies thereof)
deposited  into Escrow by Sellers  pursuant  hereto.  The Deeds and REA shall be
delivered to Buyer after  recordation.  Deliver the Letter of Credit or Security
Deposit A (as  applicable) to Lender and hold Security  Deposit B in an interest
bearing account pursuant to the provisions of this Agreement.

         10.4.5  Delivery  of  Documents  to  Sellers.  Deliver to  Sellers  one
executed  counterpart  copy of each  Lease and any other  documents  (or  copies
thereof) deposited into Escrow by Buyer pursuant hereto. After recordation,  the
Subordination,  Non-Disturbance and Attornment  Agreements shall be delivered to
Lender  with a copy to  Sellers  and  Buyer  and the  Lease  Memoranda  shall be
delivered to Buyer, with a copy to Sellers.

                                   ARTICLE 11
                            Casualty or Condemnation

11.1  Eminent  Domain or Taking.  If,  before the Close of Escrow,  any material
portion of any Property is taken or if the access  thereto or available  parking
area therefor is reduced or restricted,  by eminent domain (or is the subject of
a pending,  threatened or contemplated  taking which has not been  consummated),
Sellers shall immediately  notify Buyer of such fact. In such event, Buyer shall
have the option,  in its sole and  absolute  discretion  to (a)  terminate  this
Agreement as to the affected Property or Properties by notice to Sellers, or (b)
purchase the  Properties  without any reduction in the Purchase  Price.  Buyer's
election  shall be made by written  notice to Sellers given not later than Close
of Escrow. If Buyer does not exercise its option to terminate this Agreement, or
if there has been a nonmaterial  taking by eminent  domain,  neither party shall
have the right to terminate  this  Agreement,  but the Sellers  shall assign and
turn over,  and the Buyer shall be entitled to receive and keep that  portion of
Sellers'  condemnation  award allocable to loss of use of the condemned Property
for the period of time beginning 15 years after the Closing Date and the parties
shall proceed to the Close of Escrow without  modification  of the terms of this
Agreement  and without any  reduction in the Purchase  Price or in the base rent
payable under the applicable Lease. Unless or until this Agreement is terminated
as to a condemned  Property,  Sellers  shall take no action with  respect to any
eminent domain proceeding without the prior written consent of Buyer.

11.2  Casualty.  If,  before the Close of Escrow,  any part of any  Property  is
damaged or destroyed by casualty, Sellers shall immediately notify Buyer of such
fact. If such damage or destruction  is "material",  Buyer shall have the option
in its sole and absolute  discretion,  either to (a) terminate this Agreement as
to the  affected  Property by notice to Sellers,  or (b)  purchase  the Property
without  reduction  of the Purchase  Price.  Buyer's  election  shall be made by
written notice to the Sellers given not later than Close of Escrow. For purposes
of Article 11,  "material" shall be deemed to be any damage or destruction where
the cost of repair or  replacement  of the  affected  Property is  estimated  to
exceed the lesser of $250,000  and 5% of the  Purchase  Price  allocated to such
Property  in Exhibit 5 or shall take more than six months to repair,  in Buyer's
good faith  judgment.  If Buyer does not exercise  its option to terminate  this
Agreement or if the damage is not material, Sellers shall be entitled to receive
and keep all insurance  proceeds  payable to it with respect to such destruction
which shall then be reasonably repaired by Sellers and the parties shall proceed
to the Close of Escrow without  modification  of the terms of this Agreement and
without any  reduction in the Purchase  Price or in the base rent payable  under
the applicable  Lease, such repair by Sellers to be completed in accordance with
the provisions of the Lease.

                                   ARTICLE 12
                                 Indemnification

12.1 Brokers.  Each party  represents  and warrants to the other party that they
have not dealt with any real estate broker, agent, finder, or any other party in
connection with this transaction, except CB Richard Ellis, Inc. ("Broker") whose
commission  will be paid by Sellers  pursuant  to a separate  agreement  between
Sierra and Broker.  Each party shall indemnify and hold the other party harmless
from any loss,  liability,  damage, or expense  (including,  but not limited to,
reasonable  attorney's  fees)  resulting to the other party from a breach of the
representation   and  warranty   made  by  such  party  in  this  Section  12.1.
Notwithstanding  anything to the contrary  contained herein, the indemnities set
forth in this Article shall survive the Close of Escrow and the  termination  of
this Agreement.

12.2  Indemnification of Buyer. Sellers shall indemnify Buyer and its principals
and agents against,  and shall hold Buyer and its principals and agents harmless
from, all claims,  actions,  losses,  damages,  expenses,  reasonable attorneys'
fees, and other liabilities  (including  without  limitation tenant  improvement
costs or allowance  and  concessions  including  free rent,  if any) incurred by
Buyer  relating to the  Properties  which arise from events  which (a)  occurred
during Sellers'  ownership of the Properties or (b) which constitute a violation
of one or more  representations,  warranties or covenants of Sellers  hereunder,
and do not  relate to  obligations  or  liabilities  expressly  assumed by Buyer
hereunder.

                                   ARTICLE 13
                                     Default

13.1 Buyer's  Default.  IF THE SALE OF THE PROPERTIES DOES NOT CLOSE AS A RESULT
OF DEFAULT HEREUNDER BY BUYER,  ESCROW HOLDER SHALL DELIVER THE DEPOSIT PLUS ALL
INTEREST  ACCRUED  THEREON TO SELLERS AS  LIQUIDATED  DAMAGES AS  SELLERS'  SOLE
REMEDY. THE PARTIES AGREE THAT SELLERS' ACTUAL DAMAGES IN THE EVENT OF A DEFAULT
BY BUYER WOULD BE EXTREMELY  DIFFICULT  OR  IMPRACTICABLE  TO ASCERTAIN  AND THE
DEPOSIT PLUS ACCRUED  INTEREST  REPRESENTS THE PARTIES'  REASONABLE  ESTIMATE OF
SUCH DAMAGES.  NOTWITHSTANDING THE FOREGOING,  THIS LIQUIDATED DAMAGES PROVISION
SHALL NOT LIMIT BUYER'S INDEMNITY OBLIGATIONS UNDER SECTIONS 5.2 AND 12.1.

SELLERS' INITIALS:_______                   BUYER'S INITIALS:________

13.2  Sellers'  Default.  If the sale of the  Properties to Buyer does not close
solely as a result of default  hereunder by Sellers,  Escrow Holder shall refund
the Deposit  and all  interest  accrued  thereon to Buyer and Buyer may obtain a
decree of specific performance or may recover compensatory damages not to exceed
the  sum of  $1,150,000  plus  Buyer's  actual  out of  pocket  costs  less  any
compensatory damages recovered by Buyer under the Other Contract.  Sellers waive
the right to assert the defense of lack of  mutuality  in any suit for  specific
performance instituted by Buyer.

13.3     Survival.  The provisions of this Article shall survive the Close of
Escrow.
         ---------


                                   ARTICLE 14
                                  Miscellaneous

14.1     Notices.  All  notices  required  or  permitted  hereunder  shall be in
writing  and shall be served  on the  parties  at the following addresses:

         If to Sellers:             Sierra Health Services, Inc.
                                    2724 North Tenaya Way
                                    Las Vegas, Nevada 89128
                                    Attention:       William Godfrey
                                    Telephone:       (702) 242-7014
                                    Facsimile:       (702) 242-1532
                  and

                                    Sierra Health Services, Inc.
                                    2724 North Tenaya Way
                                    Las Vegas, Nevada 89128
                                    Attention:       Frank Collins, Esq.
                                    Telephone:       (702) 242-7189
                                    Facsimile:       (702) 242-1532

         With a copy to:            Schreck Brignone Godfrey
                                    1200 Bank of America Plaza
                                    300 South Fourth Street
                                    Las Vegas, Nevada 89101
                                    Attention:       Leslie Terry Jones, Esq.
                                    Telephone:       (702) 382-2101
                                    Facsimile:       (702) 382-8135

         If to Buyer:               CB Richard Ellis Corporate Partners, LLC
                                    c/o CB Richard Ellis Investors L.L.C.
                                    865 South Figueroa Street, Suite 3500
                                    Los Angeles, California 90017-2543
                                    Attention:       Howard Sands
                                    Telephone:       (213) 683-4200
                                    Facsimile:       (213) 683-4336

         With a copy to:            Gorman & Miller
                                    201 Santa Monica Blvd., Suite 320
                                    Santa Monica, California  90401
                                    Attention:       Ken Miller
                                    Telephone:       (310) 394-4747
                                    Facsimile:       (208) 330-9028

         Escrow Company:   Commonwealth Land Title Insurance company
                                    888 West Sixth Street
                                    Los Angeles, California 90017
                                    Attention: Lee Mellen
                                    Telephone: (213) 627-7070, Ext. 106
                                    Facsimile: (213) 627-8722

         Title Company:             Land America Title Insurance Company
                                    818 West Sixth Street
                                    Los Angeles, California 90017
                                    Attention: Valerie Poindexter Curry
                                    Telephone: (213) 627-7070, Ext. 102
                                    Facsimile: (213) 627-8722

Any such  notice  shall be either (a) sent by  certified  mail,  return  receipt
requested,  in which case notice shall be deemed  delivered  three Business Days
after  deposit,  postage  prepaid,  in the U.S. mail, (b) sent by overnight mail
delivery using a nationally recognized overnight courier, in which case it shall
be deemed  delivered one Business Day after  deposit with such  courier,  or (c)
sent by personal delivery.  The above addresses may be changed by written notice
to the other parties.

14.2  Governing Law. This Agreement is being executed and delivered in the State
of Nevada  and the laws of  Nevada  shall  govern  the  validity,  construction,
enforcement,  and interpretation of this Agreement,  unless otherwise  specified
herein.

14.3  Entirety and  Amendments.  This  Agreement  embodies the entire  agreement
between the parties and supersedes all prior agreements and  understandings,  if
any,  relating to the Properties,  and may be amended or supplemented only by an
instrument in writing executed by the party against whom enforcement is sought.

14.4  Further  Acts.  In  addition  to the acts and  documents  recited  in this
Agreement and  contemplated to be performed,  executed,  or delivered under this
Agreement,  Sellers and Buyer agree to perform,  execute and deliver or cause to
be  performed,  executed and delivered at the Close of Escrow or after the Close
of Escrow all further acts,  documents and  assurances  reasonably  necessary to
consummate the transactions  contemplated  hereby and shall use their good faith
efforts to  accomplish  the Close of Escrow in  accordance  with the  provisions
hereof.

14.5     Multiple  Counterparts.  This  Agreement  may be executed in any number
of  counterparts,  all of which taken  together  shall constitute  one and the
same  contract  and any of the  parties to this  Agreement  may  execute  the
Agreement  by signing any of the counterparts.

14.6     Exhibits.   All attached exhibits are incorporated in, and made a part
of, this Agreement for all purposes.


14.7 Assignment. Buyer shall have the right to assign its rights and obligations
under this  Agreement,  by giving prior written  notice to Sellers,  to a single
purpose  entity  approved  by the  Lender,  so long as such  assignee  expressly
assumes  the  obligations  of Buyer  hereunder.  Buyer shall also have the right
(upon  written  notice to Sellers at least one  Business  Day before the Closing
Date) to nominate  any single  purpose  entity  approved by the Lender to be the
grantee  under  any  Deed  and to be named as  Buyer  (or  Landlord)  under  the
applicable Lease, Lease Guarantee,  Seller's  Certificate and other documents to
be executed by Seller hereunder with respect to the applicable Property. Sellers
shall cooperate with Buyer and its  assignee/nominees  to effectuate the sale of
Buyer's interests hereunder with respect to any Property.  Any  assignee/nominee
shall  succeed  to all  the  rights  of  Buyer  hereunder.  Notwithstanding  the
foregoing, no such assignment/nomination  shall relieve Buyer from its liability
under this Agreement  until the Close of Escrow,  whereupon Buyer shall be fully
relieved  from any  further  liability  under  this  Agreement,  except  for its
indemnity  obligations  under  Section 5.2.  Sellers shall not have the right to
assign  their rights  under this  Agreement to any person or entity  without the
prior written consent of Buyer,  which may be withheld in the sole discretion of
Buyer.

14.8     Severability.  If any term or provision of this  Agreement is held
invalid or  unenforceable,  the remainder of this Agreement shall not be
affected.

14.9 Waivers. No waiver of any breach of this Agreement shall be deemed a waiver
of any other breach.  No extension of time for  performance of any obligation or
act shall be deemed an extension of time for performance of any other obligation
or act.

14.10  Survival  of   Representations.   The  agreements,   representations  and
warranties  made  herein  shall  survive the Close of Escrow and shall not merge
into the Deeds and the recordation thereof.

14.11  Successors and Assigns.  Subject to Section 14.7, this Agreement shall be
binding  upon and shall  inure to the benefit of the Buyer and Sellers and their
successors and assigns.

14.12  Attorneys'  Fees.  The  prevailing  party in any suit arising out of this
Agreement  shall be entitled to recover  from the losing  party all costs of the
suit, including reasonable attorneys' fees.

14.13    No Third  Party  Beneficiary.  This  contract is not  intended to give
or confer any  benefits,  rights,  privileges,  claims, actions or remedies to
any person or entity as a third party beneficiary.

14.14  Time.  Time is of the  essence  in the  performance  of  every  provision
contained in this Agreement.  If the date on which Buyer or Sellers are required
to take any action under the terms of this  Agreement is not a Business Day, the
action shall be taken on the next succeeding Business Day.

14.15  Construction.  The parties acknowledge that the parties and their counsel
have  reviewed  and  revised  this   Agreement  and  that  the  normal  rule  of
construction to the effect that any  ambiguities are to be resolved  against the
drafting party shall not be employed in the  interpretation of this Agreement or
any exhibits or amendments hereto.

14.16 Confidential Information. Buyer shall respect and observe the confidential
nature of financial, environmental and other reports and information supplied by
Sellers or obtained by Buyer concerning the Properties. If this transaction does
not close as to one or more  Properties,  Buyer  shall  return or  deliver  such
written reports as to such Properties (including any copies thereof) to Sellers.
Buyer will not disclose  publicly  (except as required by law) any  confidential
information of Sellers.  Sellers shall keep  confidential  the allocation of the
Purchase  Price among the  Properties  except that  Sellers  may  disclose  such
information to their attorneys and accountants and as required by law.

14.17  Negation  of Agency,  Partnership.  No  provision  of this  Agreement  or
subsequent  conduct of the parties  shall be construed as making either party an
agent,  principal,  partner or joint venturer with the other party, or as making
either party  responsible for the payment or reimbursement of any costs incurred
by the other party in pursuing this  transaction if this Agreement is terminated
for any reason (other than as otherwise  expressly  set forth in this  Agreement
concerning responsibility for costs).

                            [SIGNATURES ON NEXT PAGE]



<PAGE>






<PAGE>


IN WITNESS WHEREOF, Buyer and Sellers have executed this Agreement.

                              SELLERS:

                              SIERRA HEALTH SERVICES, INC.,
                              a Nevada corporation

                              By:      ____________________________

                              HEALTH PLAN OF NEVADA, INC.

                              By:      ____________________________


                              2716 NORTH TENAYA WAY LIMITED PARTNERSHIP

                              By:      SIERRA HEALTH SERVICES, INC.
                                       Its: General Partner

                              By:      ____________________________

                              BUYER:

                              CB RICHARD ELLIS CORPORATE PARTNERS, LLC,
                              a Delaware limited liability company

                              By:      CB RICHARD ELLIS INVESTORS L.L.C.,
                                       a Delaware Limited Liability Company
                                       Its:     Managing Member

                              By:      ___________________________
                                       Howard Sands, Senior Director

                              By:      ____________________________
                                       Scott Tracy, Vice President




<PAGE>






                                    EXHIBIT 1
                         Descriptions of the Properties


Property 3
The property  commonly  known as 900 South Rancho Drive,  Las Vegas,  Nevada and
consisting  of  0.362  acres of land  and  including  a two  story  building  of
approximately  12,000  square  feet  and 8  total  parking  spaces  and  legally
described on Exhibit 1C.

Property 10
Parcel 1
The  property  commonly  known as 2716 North  Tenaya  Way,  Las  Vegas,  Nevada,
consisting  of  approximately  9.57  acres of land  and  including  a six  story
building of  approximately  204,123 square feet and 909 total parking spaces and
legally described on the first page of Exhibit 1J.

Parcel A-3
Raw land  consisting  of  approximately  1.596 acres,  legally  described on the
second page of Exhibit 1J and depicted on the third page of Exhibit 1J.

Before Close of Escrow, Seller shall cause Parcel A-3 to be a separate legal and
tax parcel.


Property 11
Parcel 1
The  property  commonly  known as 2724  North  Tenaya  Way,  Las  Vegas,  Nevada
consisting  of  approximately  1.27  acres of land  and  including  a two  story
building of  approximately  43,480 square feet and 32 total  parking  spaces and
legally described on the first page of Exhibit 1K.

Parcel A-2
An uncovered  parking lot consisting of approximately 146 parking spaces legally
described  on the second  page of Exhibit 1K and  depicted  on the third page of
Exhibit 1K.

Seller  shall  complete,  before  Close  of  Escrow,  to  Buyer's  and  Lender's
reasonable satisfaction, a lot split or boundary adjustment so that the property
commonly known as 2724 North Tenaya Way includes Parcel A-2.








<PAGE>


                                    EXHIBIT 2
                                    Other Properties

                                    ---------------------------------
                                    650 N. Nellis Rd.
                                    ---------------------------------
                                    ---------------------------------
                                    888 S. Rancho Dr.
                                    ---------------------------------
                                    ---------------------------------
                                    2300 W. Charleston Blvd.
                                    ---------------------------------
                                    ---------------------------------
                                    2316 W. Charleston Blvd.
                                    --------------------------------
                                    ---------------------------------
                                    2450 W. Charleston Blvd.
                                    ---------------------------------
                                    ---------------------------------
                                    2704 N. Tenaya Way
                                    ---------------------------------
                                    ---------------------------------
                                    4475 S. Eastern Ave.
                                    ---------------------------------
                                    ---------------------------------
                                    6330 W. Flamingo Rd.
                                    ---------------------------------






<PAGE>


                                    EXHIBIT 3

                        Base Rent


                        -------------------------------- ----------------------
                        Property                         Year 1

                        -------------------------------- ----------------------
                        -------------------------------- ----------------------
                        2716 N. Tenaya Way                     4,490,705
                        -------------------------------- ----------------------
                        -------------------------------- ----------------------
                        2724 N. Tenaya Way                      956,560
                        -------------------------------- ----------------------
                        -------------------------------- ----------------------
                        900 South Rancho                        251,550
                        -------------------------------- ----------------------
                        -------------------------------- ----------------------
                        Totals:                                $
                        -------------------------------- ----------------------


Base rent for each of the  remaining  years of the primary term (years 2 through
15) of each Lease shall be adjusted upward 101.5% annually.









<PAGE>




                                    EXHIBIT 4

                                     Omitted



<PAGE>


                                    EXHIBIT 5

                          Allocation of Purchase Price



                        -------------------------------- ----------------------
                        Property                         Price ($)

                        -------------------------------- ----------------------
                        -------------------------------- ----------------------
                        2716 N. Tenaya Way                          41,500,363
                        -------------------------------- ----------------------
                        -------------------------------- ----------------------
                        2724 N. Tenaya Way                           9,217,190
                        -------------------------------- ----------------------
                        -------------------------------- ----------------------
                        900 South Rancho Drive                       2,423,877
                        -------------------------------- ----------------------
                        -------------------------------- ----------------------
                        Totals:                                     $
                        -------------------------------- ----------------------




         This  allocation  may be  modified  by a  writing  signed  by Buyer and
Sellers.


<PAGE>


                                    EXHIBIT 6

                                 Disclosure List



                               FIRST AMENDMENT TO
                           PURCHASE AND SALE AGREEMENT

                  This First  Amendment  to  Purchase  and Sale  Agreement  (the
"First Amendment"), dated as of December 8, 2000, is entered into by and between
Sierra Health Services,  Inc., a Nevada corporation  ("Sierra"),  Health Plan of
Nevada,  Inc. ("HPN"),  Sierra Health and Life Insurance Company,  Inc. ("Sierra
Health"),  2716 North Tenaya Way Limited Partnership  ("Tenaya  Partnership" and
together  with Sierra,  HPN,  Sierra  Health,  "Sellers"),  and CB Richard Ellis
Corporate Partners, LLC, a Delaware limited liability company ("Buyer").

                                 R E C I T A L S

     A.  Sellers  and  Buyer  are  parties  to that  certain  Purchase  and Sale
Agreement dated as of December 1, 2000 (the "Agreement").

     B. The  Agreement  provides  that  certain  matters are to  transpire on or
before December 8, 2000.

     C. The parties  wish to extend the  December 8, 2000  deadline on the terms
and conditions set forth herein.

         NOW,  THEREFORE,  for and in  consideration of the mutual covenants and
agreements hereinafter set forth, the parties agree as follows:

     1. The first  sentence  in the  definition  of "Due  Diligence  Period"  in
Section 1.1 is hereby deleted and replaced with the following language:

                  "Due  Diligence  Period"  shall mean the period  ending on the
                  later of December 15, 2000 or the date on which Buyer receives
                  written approval from Sellers' bank for this transaction.

     2. The second  sentence of Section 2.2.3 of the Agreement is hereby deleted
and replaced with the following language:

                  In the  event  the  parties  have not  negotiated  a  mutually
                  acceptable  form of Lease  and  Lease  Guaranty  by  midnight,
                  Pacific  Standard Time,  December 11, 2000,  either Sellers or
                  Buyer may elect to terminate  this Agreement by written notice
                  to the other party(ies) and to Escrow Holder.

     3. All of the  provisions of the  Agreement  shall remain in full force and
effect.

     4. This First  Amendment  may be executed  in  counterparts  and  facsimile
signatures hereon shall have the same force and effect as originals.

                             Signature page follows

         IN WITNESS WHEREOF, Buyer and Sellers have executed this Agreement.

                          SELLERS:

                          SIERRA HEALTH SERVICES, INC.,
                          a Nevada corporation

                          By:      ____________________________


                          HEALTH PLAN OF NEVADA, INC.

                          By:      ____________________________

                          2716 NORTH TENAYA WAY LIMITED PARTNERSHIP

                          By:      SIERRA HEALTH SERVICES, INC.
                          Its:     General Partner

                          By:      ____________________________

                          SIERRA HEALTH & LIFE INSURANCE, INC.

                          By:      _____________________________

                          BUYER:

                          CB RICHARD ELLIS CORPORATE PARTNERS, LLC, a Delaware
                          limited liability company

                          By:      CB RICHARD ELLIS INVESTORS L.L.C., a Delaware
                                   Limited Liability company
                                   Its:     Managing Member

                                   By:      ___________________________
                                            Howard Sands, Senior Director

                                   By:      ____________________________
                                            Scott Tracy, Vice President


<PAGE>


                               SECOND AMENDMENT TO
                           PURCHASE AND SALE AGREEMENT

                  This Second  Amendment  to Purchase  and Sale  Agreement  (the
"Second  Amendment"),  dated as of December  11,  2000,  is entered  into by and
between Sierra Health Services,  Inc., a Nevada corporation  ("Sierra"),  Health
Plan of Nevada,  Inc. ("HPN"),  Sierra Health and Life Insurance  Company,  Inc.
("Sierra  Health"),   2716  North  Tenaya  Way  Limited   Partnership   ("Tenaya
Partnership" and together with Sierra,  HPN, Sierra Health,  "Sellers"),  and CB
Richard Ellis Corporate  Partners,  LLC, a Delaware  limited  liability  company
("Buyer").

                                 R E C I T A L S

     A.  Sellers  and  Buyer  are  parties  to that  certain  Purchase  and Sale
Agreement dated as of December 1, 2000, as amended (the "Agreement").

     B. The  Agreement  provides  that  certain  matters are to  transpire on or
before December 11, 2000.

     C. The parties wish to extend the  December 11, 2000  deadline on the terms
and conditions set forth herein.

     NOW,  THEREFORE,  for and in  consideration  of the  mutual  covenants  and
agreements hereinafter set forth, the parties agree as follows:

     1. The second  sentence of Section 2.2.3 of the Agreement is hereby deleted
and replaced with the following language:

                  In the  event  the  parties  have not  negotiated  a  mutually
                  acceptable  form of Lease  and  Lease  Guaranty  by  midnight,
                  Pacific  Standard Time,  December 14, 2000,  either Sellers or
                  Buyer may elect to terminate  this Agreement by written notice
                  to the other party(ies) and to Escrow Holder.

     2. The second  sentence of Section 4.2 is hereby  deleted and replaced with
the following language:

                  Buyer  shall have until  December  14, 2000 in which to review
                  all maters reflected in those documents.

     3. All of the  provisions of the  Agreement  shall remain in full force and
effect.

     4. This Second  Amendment  may be executed in  counterparts  and  facsimile
signatures hereon shall have the same force and effect as originals.

                             Signature page follows

         IN  WITNESS  WHEREOF,  Buyer and  Sellers  have  executed  this  Second
Amendment.

                                    SELLERS:

                                    SIERRA HEALTH SERVICES, INC.,
                                            a Nevada corporation

                                    By:      ____________________________


                                    HEALTH PLAN OF NEVADA, INC.

                                    By:      ____________________________

                                    2716 NORTH TENAYA WAY LIMITED PARTNERSHIP

                                    By:      SIERRA HEALTH SERVICES, INC.
                                    Its:     General Partner

                                    By:      ____________________________

                                    SIERRA HEALTH & LIFE INSURANCE, INC.

                                    By:      _____________________________

                                    BUYER:

                                    CB RICHARD ELLIS CORPORATE PARTNERS, LLC, a
                                    Delaware limited liability company

                                    By:    CB RICHARD ELLIS INVESTORS L.L.C.,
                                           a Delaware Limited Liability company
                                    Its:   Managing Member

                                    By:      ___________________________
                                             Howard Sands, Senior Director

                                    By:      ____________________________
                                             Scott Tracy, Vice President



                               THIRD AMENDMENT TO
                           PURCHASE AND SALE AGREEMENT

                  This Third  Amendment  to  Purchase  and Sale  Agreement  (the
"Third  Amendment"),  dated as of  December  14,  2000,  is entered  into by and
between Sierra Health Services,  Inc., a Nevada corporation  ("Sierra"),  Health
Plan of Nevada,  Inc. ("HPN"),  Sierra Health and Life Insurance  Company,  Inc.
("Sierra  Health"),   2716  North  Tenaya  Way  Limited   Partnership   ("Tenaya
Partnership" and together with Sierra,  HPN, Sierra Health,  "Sellers"),  and CB
Richard Ellis Corporate  Partners,  LLC, a Delaware  limited  liability  company
("Buyer").

                                                      R E C I T A L S

     A.  Sellers  and  Buyer  are  parties  to that  certain  Purchase  and Sale
Agreement dated as of December 1, 2000, as amended (the "Agreement").

     B. The  Agreement  provides  that  certain  matters are to  transpire on or
before December 14, 2000.

     C. The parties wish to extend the December 14, 2000  deadline as to certain
matters on the terms and conditions set forth herein and acknowledge  receipt of
certain items.

         NOW,  THEREFORE,  for and in  consideration of the mutual covenants and
agreements hereinafter set forth, the parties agree as follows:

     1. The second  sentence of Section 2.2.3 of the Agreement is hereby deleted
and replaced with the following language:

                  In the  event  the  parties  have not  negotiated  a  mutually
                  acceptable  form of Lease  and  Lease  Guaranty  by  midnight,
                  Pacific  Standard Time,  December 15, 2000,  either Sellers or
                  Buyer may elect to terminate  this Agreement by written notice
                  to the other party(ies) and to Escrow Holder.

         2. The Sellers  acknowledge  receipt of  objections to title and survey
set forth in the  Memorandum  from David Kraus dated  12-13-00 sent via email to
Sellers on December 13, 2000. Such objections shall be deemed to have been given
on December 13, 2000 in  compliance  with the deadline and notice  provisions of
the Agreement.

     3. All of the  provisions of the  Agreement  shall remain in full force and
effect.

     4. This Third  Amendment  may be executed  in  counterparts  and  facsimile
signatures hereon shall have the same force and effect as originals.

                             Signature page follows

         IN  WITNESS  WHEREOF,  Buyer  and  Sellers  have  executed  this  Third
Amendment.

                                   SELLERS:

                                   SIERRA HEALTH SERVICES, INC.,
                                   a Nevada corporation

                                   By:      ____________________________


                                   HEALTH PLAN OF NEVADA, INC.

                                   By:      ____________________________

                                   2716 NORTH TENAYA WAY LIMITED PARTNERSHIP

                                   By:      SIERRA HEALTH SERVICES, INC.
                                   Its:     General Partner

                                   By:      ____________________________

                                   SIERRA HEALTH & LIFE INSURANCE, INC.

                                   By:      _____________________________

                                   BUYER:

                                   CB RICHARD ELLIS CORPORATE PARTNERS, LLC,
                                   a Delaware limited liability company

                                   By:      CB RICHARD ELLIS INVESTORS L.L.C.,
                                            a Delaware Limited Liability company
                                            Its:     Managing Member

                                   By:      ___________________________
                                            Howard Sands, Senior Director

                                   By:      ____________________________
                                            Scott Tracy, Vice President

                               FOURTH AMENDMENT TO
                           PURCHASE AND SALE AGREEMENT

                  This Fourth  Amendment  to Purchase  and Sale  Agreement  (the
"Fourth  Amendment"),  dated as of December  15,  2000,  is entered  into by and
between Sierra Health Services,  Inc., a Nevada corporation  ("Sierra"),  Health
Plan of Nevada,  Inc. ("HPN"),  Sierra Health and Life Insurance  Company,  Inc.
("Sierra  Health"),   2716  North  Tenaya  Way  Limited   Partnership   ("Tenaya
Partnership"  and together  with Sierra,  HPN,  Sierra  Health,  "Sellers"),  CB
Richard Ellis Corporate  Partners,  LLC, a Delaware  limited  liability  company
("Assignor") and CPSIEO, LLC, a Delaware limited liability company ("Buyer").

                                                      R E C I T A L S

     A.  Sellers and  Assignor  are parties to that  certain  Purchase  and Sale
Agreement dated as of December 1, 2000, as amended (the "Agreement").

     B. The parties wish to extend  certain  deadlines as to certain  matters on
the terms and  conditions  set forth herein and  acknowledge  receipt of certain
items.

         NOW,  THEREFORE,  for and in  consideration of the mutual covenants and
agreements hereinafter set forth, the parties agree as follows:

     1. The second  sentence of Section 2.2.3 of the Agreement is hereby deleted
and replaced with the following language:

                  In the  event  the  parties  have not  negotiated  a  mutually
                  acceptable  form of Lease  and  Lease  Guaranty  by  midnight,
                  Pacific  Standard Time,  December 18, 2000,  either Sellers or
                  Buyer may elect to terminate  this Agreement by written notice
                  to the other party(ies) and to Escrow Holder.

         2. Assignor  hereby  notifies  Sellers that pursuant to Section 14.7 of
the Agreement, it has assigned its rights and obligations under the Agreement to
Buyer effective December 15, 2000.

     3. The  "Extended  Review  Period"  shall be extended to midnight,  Pacific
Standard  Time,  December 19, 2000.  All of the  provisions  of the Agreement as
amended hereby shall remain in full force and effect.

     4. This Fourth  Amendment  may be executed in  counterparts  and  facsimile
signatures hereon shall have the same force and effect as originals.

                             Signature page follows



         IN WITNESS WHEREOF, the parties have executed this Fourth Amendment.

                          SELLERS:

                          SIERRA HEALTH SERVICES, INC.,
                          a Nevada corporation

                          By:      ____________________________


                          HEALTH PLAN OF NEVADA, INC.

                          By:      ____________________________

                          2716 NORTH TENAYA WAY LIMITED PARTNERSHIP

                          By:      SIERRA HEALTH SERVICES, INC.
                          Its:     General Partner

                          By:      ____________________________

                          SIERRA HEALTH & LIFE INSURANCE, INC.

                          By:      _____________________________

                          ASSIGNOR:

                          CB RICHARD ELLIS CORPORATE PARTNERS, LLC, a Delaware
                          limited liability company

                          By:      CB RICHARD ELLIS INVESTORS L.L.C., a Delaware
                                   Limited Liability company
                                   Its:     Managing Member

                          By:      ___________________________
                                   Howard Sands, Senior Director

                          By:      ____________________________
                                   Scott Tracy, Vice President



                          BUYER:

                          CPSIEO, LLC, a Delaware limited liability company

                          By:      ___________________________
                                   Howard Sands, Manager




                               FIFTH AMENDMENT TO
                           PURCHASE AND SALE AGREEMENT


         This  Fifth  Amendment  to  Purchase  and Sale  Agreement  (the  "Fifth
Amendment"),  dated as of  December  18,  2000,  is entered  into by and between
Sierra Health Services,  Inc., a Nevada corporation  ("Sierra"),  Health Plan of
Nevada,  Inc. ("HPN"),  Sierra Health and Life Insurance Company,  Inc. ("Sierra
Health"),  2716 North Tenaya Way Limited Partnership  ("Tenaya  Partnership" and
together  with  Sierra,  HPN,  Sierra  Health,  "Sellers"),  and CPSIEO,  LLC, a
Delaware limited liability company ("Buyer").


                                 R E C I T A L S

     A.  Sellers and  Assignor  are parties to that  certain  Purchase  and Sale
Agreement dated as of December 1, 2000, as amended (the "Agreement").

     B. The parties wish to extend  certain  deadlines as to certain  matters on
the terms and  conditions  set forth herein and  acknowledge  receipt of certain
items.

         NOW,  THEREFORE,  for and in  consideration of the mutual covenants and
agreements hereinafter set forth, the parties agree as follows:

     1. The second  sentence of Section 2.2.3 of the Agreement is hereby deleted
and replaced with the following language:

                  In the  event  the  parties  have not  negotiated  a  mutually
                  acceptable  form of Lease  and  Lease  Guaranty  by  midnight,
                  Pacific  Standard Time,  December 19, 2000,  either Sellers or
                  Buyer may elect to terminate  this Agreement by written notice
                  to the other party(ies) and to Escrow Holder.

     2. This Fifth  Amendment  may be executed  in  counterparts  and  facsimile
signatures hereon shall have the same force and effect as originals.



                             Signature page follows


<PAGE>



         IN WITNESS WHEREOF, the parties have executed this Fifth Amendment.

                          SELLERS:

                          SIERRA HEALTH SERVICES, INC.,
                          a Nevada corporation

                          By:      ____________________________


                          HEALTH PLAN OF NEVADA, INC.

                          By:      ____________________________

                          2716 NORTH TENAYA WAY LIMITED PARTNERSHIP

                          By:      SIERRA HEALTH SERVICES, INC.
                          Its:     General Partner

                          By:      ____________________________

                          SIERRA HEALTH & LIFE INSURANCE, INC.

                          By:      _____________________________

                          BUYER:

                          CPSIEO, LLC, a Delaware limited liability company

                          By:      ___________________________
                                   Howard Sands, Manager



                               SIXTH AMENDMENT TO
                           PURCHASE AND SALE AGREEMENT


         This  Sixth  Amendment  to  Purchase  and Sale  Agreement  (the  "Sixth
Amendment"),  dated as of  December  19,  2000,  is entered  into by and between
Sierra Health Services,  Inc., a Nevada corporation  ("Sierra"),  Health Plan of
Nevada,  Inc. ("HPN"),  Sierra Health and Life Insurance Company,  Inc. ("Sierra
Health"),  2716 North Tenaya Way Limited Partnership  ("Tenaya  Partnership" and
together  with  Sierra,  HPN,  Sierra  Health,  "Sellers"),  and CPSIEO,  LLC, a
Delaware limited liability company ("Buyer").


                                 R E C I T A L S

     A.  Sellers  and  Buyer  are  parties  to that  certain  Purchase  and Sale
Agreement dated as of December 1, 2000, as amended (the "Agreement").

     B. The parties wish to extend  certain  deadlines as to certain  matters on
the terms and conditions set forth herein.

         NOW,  THEREFORE,  for and in  consideration of the mutual covenants and
agreements hereinafter set forth, the parties agree as follows:

     1. The second  sentence of Section 2.2.3 of the Agreement is hereby deleted
and replaced with the following language:

                  In the  event  the  parties  have not  negotiated  a  mutually
                  acceptable  form of Lease  and  Lease  Guaranty  by  midnight,
                  Pacific  Standard Time,  December 20, 2000,  either Sellers or
                  Buyer may elect to terminate  this Agreement by written notice
                  to the other party(ies) and to Escrow Holder.

     2. This Sixth  Amendment  may be executed  in  counterparts  and  facsimile
signatures hereon shall have the same force and effect as originals.



                             Signature page follows


<PAGE>



         IN WITNESS WHEREOF, the parties have executed this Sixth Amendment.

                          SELLERS:

                          SIERRA HEALTH SERVICES, INC.,
                          a Nevada corporation

                          By:      ____________________________


                          HEALTH PLAN OF NEVADA, INC.

                          By:      ____________________________

                          2716 NORTH TENAYA WAY LIMITED PARTNERSHIP

                          By:      SIERRA HEALTH SERVICES, INC.
                          Its:     General Partner

                          By:      ____________________________

                          SIERRA HEALTH & LIFE INSURANCE, INC.

                          By:      _____________________________

                          BUYER:

                          CPSIEO, LLC, a Delaware limited liability company

                          By:      ___________________________
                                   Howard Sands, Manager



                              SEVENTH AMENDMENT TO
                           PURCHASE AND SALE AGREEMENT


         This Seventh  Amendment to Purchase and Sale  Agreement  (the  "Seventh
Amendment"),  dated as of  December  20,  2000,  is entered  into by and between
Sierra Health Services,  Inc., a Nevada corporation  ("Sierra"),  Health Plan of
Nevada,  Inc. ("HPN"),  Sierra Health and Life Insurance Company,  Inc. ("Sierra
Health"),  2716 North Tenaya Way Limited Partnership  ("Tenaya  Partnership" and
together  with  Sierra,  HPN,  Sierra  Health,  "Sellers"),  and CPSIEO,  LLC, a
Delaware limited liability company ("Buyer").


                                 R E C I T A L S

     A.  Sellers  and  Buyer  are  parties  to that  certain  Purchase  and Sale
Agreement dated as of December 1, 2000, as amended (the "Agreement").

     B. The parties wish to extend  certain  deadlines as to certain  matters on
the terms and conditions set forth herein.

         NOW,  THEREFORE,  for and in  consideration of the mutual covenants and
agreements hereinafter set forth, the parties agree as follows:

     1. The second  sentence of Section 2.2.3 of the Agreement is hereby deleted
and replaced with the following language:

                  In the  event  the  parties  have not  negotiated  a  mutually
                  acceptable  form of Lease  and  Lease  Guaranty  by  midnight,
                  Pacific  Standard Time,  December 21, 2000,  either Sellers or
                  Buyer may elect to terminate  this Agreement by written notice
                  to the other party(ies) and to Escrow Holder.

     2. This Seventh  Amendment  may be executed in  counterparts  and facsimile
signatures hereon shall have the same force and effect as originals.



                             Signature page follows


<PAGE>



         IN WITNESS WHEREOF, the parties have executed this Seventh Amendment.

                          SELLERS:

                          SIERRA HEALTH SERVICES, INC.,
                          a Nevada corporation

                          By:      ____________________________


                          HEALTH PLAN OF NEVADA, INC.

                          By:      ____________________________

                          2716 NORTH TENAYA WAY LIMITED PARTNERSHIP

                          By:      SIERRA HEALTH SERVICES, INC.
                          Its:     General Partner

                          By:      ____________________________

                          SIERRA HEALTH & LIFE INSURANCE, INC.

                          By:      _____________________________

                          BUYER:

                          CPSIEO, LLC, a Delaware limited liability company

                          By:      ___________________________
                                   Howard Sands, Manager