<PAGE>
                                                                  EXHIBIT 10.1

Bell Plaine Financial LLC
June 26, 1998


Mr. Steven Hertel
President & Chief Executive Officer
Regency Bancorp
7060 North Fresno Street
P.O. Box 16279
Fresno, CA  93755-6279


Dear Mr. Hertel:

     This letter will confirm that Regency Bancorp ("Regency") has engaged 
Belle Plaine Financial, LLC ("Belle Plaine") as the exclusive financial 
advisor to Regency and any entities it may form, acquire or invest in 
(collectively, the "Company") in connection with the Company's efforts to (a) 
acquire or invest in other depository institutions, excepting therefrom the 
opening of individual bank branches in the ordinary course of business; (b) 
acquire, invest or sell businesses other than depository institutions, 
excepting therefrom transactions between such businesses and the Company that 
have a Transaction Value (as defined below) of less than $1 million, (c) 
effect a sale of the Company or a material amount of its assets; or (d) 
pursue a financing or recapitalization transaction (collectively, the 
"Transaction").

1.   In connection with a proposed Transaction, at the request of the Company,
     Belle Plaine will provide such services as the Company shall reasonably
     request including: (i) assisting the Company in the structuring of the
     financial aspects of a Transaction; (ii) identifying alternative potential
     parties and contacting such parties as the Company may designate; (iii)
     negotiating the terms of a Transaction with such parties; (iv) assisting
     the Company in communicating the strategic implications of the Transaction
     to the investment community; and (v) advising the Company in connection
     with its efforts to raise any additional capital that may be required to
     facilitate the Transaction.

2.   In connection with a proposed Transaction, you will furnish Belle Plaine
     with such material regarding the business and financial condition of the
     Company as we request, all of which will be accurate and complete in all
     material respects at the time furnished.  The Company will also use its
     best efforts to assure that its personnel, consultants, experts, attorneys
     and accountants are made available to Belle Plaine upon Belle Plaine's
     reasonable request in connection with services provided or to be provided
     by Belle Plaine.  During the term of this agreement, the Company shall
     promptly notify Belle Plaine of (i) any material changes in the business or
     financial condition of the Company from the information provided to Belle
     Plaine, and (ii) any material events or developments relating to the
     financial condition or business operations or prospects of the Company and
     promptly make available for Belle Plaine's review copies of all filings
     made by the Company with any regulatory agency and copies of all press
     releases issued by the Company.  We are relying, without independent
     verification, on the accuracy and completeness of all 


<PAGE>

BPF
Regency Bancorp                                                    June 3, 1998

                                                                    Page 2 of 7

     information furnished to us by the Company or any other party or potential 
     party to any Transaction.  Belle Plaine agrees that all requests for 
     information from the Company will be directed only to the President or 
     Chairman of the Board of the Company or such other persons as the 
     President or Chairman shall specifically designate and that it will not 
     treat information obtained from any other person or source as having been 
     provided by the Company.  In addition, Belle Plaine agrees to keep any 
     such non-public information confidential so long as it remains non-public, 
     unless disclosure is required by law or requested by any governmental or 
     regulatory agency or body, and Belle Plaine will not make any use thereof, 
     except in connection with our services hereunder for the Company.  Any 
     advice rendered by Belle Plaine pursuant to this letter shall not be 
     disclosed in any manner without Belle Plaine's prior written approval and 
     will be treated by the Company and Belle Plaine as confidential.

3.   In consideration of the services to be provided hereunder, the Company
     agrees to pay to Belle Plaine the following cash fees:

     (A)  $5,000 upon the signing of this letter agreement and $5,000 at the
          beginning of each fiscal quarter beginning July 1, 1998,

     (B)  In the event that a sale of the Company is completed, an amount equal
          to one and one-half percent (1.5%) of the Transaction Value (as
          defined below) for the Transaction, net the cost of a "fairness
          opinion" if such opinion is deemed necessary,

     (C)  In the event that an acquisition of or investment in another financial
          institution is completed by the Company, an amount based upon the
          following schedule will be owed to Belle Plaine upon the consummation
          of the acquisition based upon the Transaction Value for the 
          Transaction, net the cost of a "fairness opinion" if such opinion is 
          deemed necessary:

<TABLE>
<CAPTION>
                         Deal Value
                       ($ in millions)                   Fees
                       ---------------                   ----
          <S>  <C>  <C>                <C>        <C>    <C>
          (1)  If   $ 0 LESS THAN      $20        then   2.0%

          (2)  If   $20 LESS THAN      $50        then   $400,000, plus 1.5% of amount in 
                        OR EQUAL TO                      excess of $20 million, up to $50 
                                                         million

          (3)  If   $50 GREATER THAN              then   $850,000, plus 1.0% of amount in 
                                                         excess of $50 million
</TABLE>

     (D)  In the event of a financing or recapitalization, the fees will be
          determined in accordance with paragraph 8 below.
     

<PAGE>

BPF
Regency Bancorp                                                    June 3, 1998

                                                                    Page 3 of 7

     (E)  Fees payable pursuant to paragraphs 3 (B), (C) and (D) shall be paid
          upon and only upon the closing of the Transaction.

     For purposes of this agreement, "Transaction Value" means the sum of (i) 
with respect to each class of capital stock of the Company in the event of a 
sale of the Company or of the financial institution which is acquired by the 
Company or in which the Company invests, the product of (a) the highest 
consideration paid or payable for a share of such class of capital stock 
determined as described in the following paragraph and (b) the sum of (1) the 
total number of shares of such class of capital stock of the Company or such 
financial institution plus (2) the number of shares of such class issuable 
upon exercise of options, warrants or other rights, or conversion or exchange 
of securities to the extent that such options are then exercisable; (ii) the 
aggregate liquidation value of any preferred stock or other preferential 
interests redeemed or remaining outstanding; (iii) the fair market value of 
any assets distributed to the shareholders of the Company or such financial 
institution that are purchased; and (iv) the consideration paid or payable 
for the assets of the Company or the assets of another financial institution, 
as the case may be.

     The determination of the "consideration paid or payable for a share of 
such class of capital stock" in connection with the Transaction shall include 
cash, securities (valued in accordance with the following paragraph), or 
other assets or consideration paid or payable by the purchaser or any of its 
affiliates, as the case may be, determined without regard to any allocations 
between the Company or its affiliates in the event of a sale of the Company 
or between the financial institution or its affiliates in the event such 
financial institution is acquired by the Company or the Company invests in 
such financial institution, including but not limited to (i) assets (net of 
debt or payables) of the Company or such financial institution retained by 
the Company or such financial institution or their respective stockholders 
and affiliates, as the case may be, (ii) any deferred installments of the 
purchase price, (iii) any portion of the purchase price held in escrow 
subsequent to closing which is payable pursuant to the terms of the escrow 
arrangement, irrespective of whether such amounts are in fact paid, (iv) any 
extraordinary compensation paid directly or indirectly by the purchaser to 
principals, management or employees of the Company or affiliates of the 
Company in connection with or in anticipation of the Transaction or by the 
Company to principals, management or employees of a financial institution 
acquired by the Company or in which the Company invests, including but not 
limited to cash payments, stock or option grants, consulting arrangements and 
non-competition arrangements, (v) any payments to the Company or the 
financial institution and their respective affiliates for non-competition 
agreements, (vi) any payments pursuant to earn-outs, royalties or other 
similar arrangements, (vii) any payments payable after closing upon the 
occurrence of certain contingencies or conditions or the satisfaction of 
certain earnings, sales levels or other performance objectives which are 
agreed to on or before the closing, irrespective of whether such amounts are 
in fact paid, (vii) the amount of any dividends or other extraordinary 
payments or distributions to stockholders of the Company or the financial 
institution in connection with or in anticipation of the Transaction, and 
(iv) consideration paid by the purchaser or its affiliates as a deposit, 
reimbursement of expenses, liquidated damages, walk-away fee or other 
arrangement.

     In the event that all or any portion of the Transaction Value for a 
Transaction is paid in stock or other securities, deferred installments or 
other non-cash consideration, the amount of the fee payable 

<PAGE>

BPF
Regency Bancorp                                                    June 3, 1998

                                                                    Page 4 of 7


with respect to such items shall be determined on the basis of the fair 
market cash equivalent value of such non-cash consideration as of the day 
preceding the closing date of the Transaction as reasonably determined by 
Belle Plaine and the Company, provided that the value of securities (received 
as consideration) which have an existing public trading market shall be 
determined by the average closing sale (trade) price for such securities 
during the five trading days immediately preceding the closing date.

     Any portion of the fee which is payable with respect to any earn-out, 
royalty or similar arrangement where the amount payable is not a certain 
amount, shall be calculated and paid at the closing based upon the estimated 
net present value thereof as reasonably determined by Belle Plaine and the 
Company.

     If a Transaction takes the form of a purchase of assets and an 
assumption of liabilities, then the "Transaction Value" of the Company or the 
financial institution shall be deemed to include the amount of cash, 
securities, or other consideration paid to the Company or the financial 
institution and their respective shareholders, and affiliates, as the case 
may be, in respect of the assets, plus the aggregate face amount of all 
liabilities, including accounts payable, accruals, and income taxes payable 
of the Company, or the financial institution, assumed by the purchaser and 
its affiliates or the Company, as the case may be.

     If a Transaction involves the acquisition of less than all of the 
Company's outstanding equity securities, then the fee payable pursuant to 
Section 3(B) shall nonetheless be calculated as though all such equity 
securities had been so acquired by the purchaser.

4.   Regardless of whether a Transaction is completed, the Company will 
     reimburse Belle Plaine, upon its demand, for all reasonable out-of-pocket
     expenses (including travel expenses and fees and disbursements of counsel
     retained by Belle Plaine in connection with this engagement).  In addition
     to professional fees, our billing statements include reimbursable expenses
     normally incurred in the conduct of the work.  The reimbursable expenses
     will include a flat ten percent of Belle Plaine's monthly costs for data
     services, telephone, fax, postage and general office expenses which will be
     categorized on our statement as indirect expenses, but excluding any
     allocation for employee costs or debt service costs.
  
5.   The Company agrees to indemnify and hold Belle Plaine harmless in 
     accordance with the terms and conditions of Appendix A attached hereto 
     and made a part hereof as though fully set forth in this agreement.  No 
     termination or modification hereof, or completion of Belle Plaine's 
     engagement hereunder, shall limit or affect such indemnification.

6.   Belle Plaine's services hereunder may be terminated by the Company or Belle
     Plaine at any time upon 30 days written notice, provided that Belle Plaine
     shall be entitled to any fees payable pursuant to Section 3 and Section 8
     hereof in the event that the Company completes a Transaction (i) on which
     Belle Plaine provided advice or participated in discussions with any of the
     investors in such Transaction or (ii) with any of the parties as to which
     Belle Plaine advised the Company or with whom the Company engaged in

<PAGE>

BPF
Regency Bancorp                                                    June 3, 1998

                                                                    Page 5 of 7


     discussions regarding a possible Transaction prior to the termination of
     this letter agreement, providing that (i) in the event the Company 
     terminated this agreement, such Transaction is completed within two years
     following the termination of this letter agreement or (ii) in the event
     Belle Plaine terminated this agreement, the Company executes an agreement
     in connection with a proposed Transaction within one year following the
     termination of this letter agreement.  In addition, Belle Plaine shall
     remain entitled to the reimbursement of fees and expenses under the terms
     and conditions described in Section 4 hereof, to the extent the same have
     been incurred on or prior to the date of such termination and to the
     quarterly retainer fee under Section 3(A) to the extent payable prior to
     the termination date.  Furthermore, the provisions of this Section 6, and
     Sections 2, 5 (including Appendix A), 8, 10, 12, 13, 14, and 15 shall
     survive any termination of this agreement.

7.   In order to coordinate our efforts with respect to any Transaction, during
     the period of our engagement hereunder neither the Company nor any 
     representative thereof (other than Belle Plaine) will initiate discussions
     regarding a Transaction except through Belle Plaine.  If the Company or its
     management receives an inquiry regarding a Transaction, they will promptly
     advise Belle Plaine of such inquiry in order that we can evaluate such
     prospective party and its interest and assist the Company in any resulting
     negotiations.

8.   It is understood and agreed that if the Company decides to pursue a
     financing or recapitalization Transaction for which Belle Plaine provided
     any of the financial advisory services described above in Section 1 hereof,
     the Company and Belle Plaine shall negotiate in good faith acceptable
     compensation for Belle Plaine in consideration of such services, which
     compensation will take into account, among other things, the results
     obtained and the custom and practice among investment bankers acting in
     similar situations.  In consideration of the financial services rendered
     pursuant to a financing or recapitalization Transaction, the compensation
     payable to Belle Plaine for such services rendered shall not exceed five
     percent (5%) of the Transaction Value in cash compensation plus warrants to
     purchase an aggregate amount of common stock equal to five percent (5%) of
     the newly issued common stock to be outstanding subsequent to the 
     completion of the financing or recapitalization Transaction.  The 
     compensation owed to Belle Plaine in accordance with the fee structure 
     agreed upon by the Company and Belle Plaine in respect of a financing or 
     recapitalization Transaction shall be paid to Belle Plaine in cash upon 
     the consummation of any such Transaction.

9.   Except as expressly provided herein, no fee paid or payable to Belle Plaine
     or any of its affiliates shall be used as an offset or credit against any
     other fee paid or payable to Belle Plaine or any of its affiliates.

10.  This agreement, including the indemnity in Appendix A, embodies the sole
     terms of the agreement between the Company and Belle Plaine with respect to
     the subject matter hereof and supersedes all previous agreements, whether
     oral or written, between the Company and Belle Plaine with respect to the
     subject matter hereof.  This letter agreement shall be governed by and
     construed in accordance with the laws of the State of California without

<PAGE>

BPF
Regency Bancorp                                                    June 3, 1998

                                                                    Page 6 of 7


     regard to principles of conflict of laws.  Any right to trial by jury with
     respect to any claim or proceeding related to or arising out of this
     engagement or any transaction or conduct in connection herewith, is waived.
     Any claim or dispute arising out of this agreement or the alleged breach
     thereof shall be submitted by the parties to binding and nonappealable
     arbitration by JAMS/Endispute ("JAMS") in Fresno, California, under the
     commercial rules then in effect for JAMS, except as provided herein. 
     Provided that JAMS is not suitable to arbitrate such claim or dispute, then
     such claim or dispute shall be submitted by the parties to binding and
     nonappealable arbitration by the American Arbitration Association ("AAA")
     in Fresno, California, under the commercial rules then in effect for the
     AAA, except as provided herein.  JAMS, or in the event that JAMS is deemed
     unsuitable to arbitrate such claim or dispute, the AAA shall recommend
     three arbitrators who are knowledgeable in the field of investment banking.
     The parties shall agree upon one of the three arbitrators or, if no
     arbitrator is mutually agreed upon, JAMS or the AAA, as the case may be,
     shall appoint one of the three arbitrators within 30 days of such failure. 
     The award rendered by the arbitrator shall include costs of arbitration,
     reasonable attorneys' fees and fees of experts and other witnesses, but
     shall not include punitive damages against either party.  Each party shall
     have the right to request the arbitrator to order reasonable and limited
     discovery.  Notwithstanding this provision, appropriate injunctive relief
     may be sought by either party.

11.  This agreement may be executed in counterparts, each of which shall be
     deemed an original and all of which shall continue one and the same
     instrument.

12.  The obligations of the Company hereunder shall be the joint and several
     obligations of the entities comprising the term Company.

13.  The Company expressly acknowledges that Belle Plaine has been retained
     solely as an advisor to the Company, and not as an advisor to or agent of
     any other person, and that the Company's engagement of Belle Plaine is not
     intended to confer rights upon any persons not a party hereto (including
     shareholders, employees or creditors of the Company) as against Belle
     Plaine, Belle Plaine's affiliates or their respective directors, officers,
     agents and employees. Any advice provided to the Company by Belle Plaine
     pursuant to this agreement is solely for the information and assistance of
     the Board of Directors of the Company.  Such advice shall be treated as
     confidential information, shall not be disclosed publicly in any manner
     without Belle Plaine's prior written approval and shall not be relied upon
     by the Company's shareholders or any third party.  Any reference to Belle
     Plaine or to any affiliate of Belle Plaine in any release or communication
     to any party outside the Company is subject to Belle Plaine's prior written
     approval, which approval shall not be unreasonably withheld or delayed.  If
     this agreement is terminated prior to any release or communication, no
     reference shall be made to Belle Plaine without Belle Plaine's prior
     written approval.

14.  Belle Plaine represents that it has the necessary expertise to provide the
     services contemplated by this agreement and that the compensation provided
     for herein is fair and reasonable and comparable to the compensation which
     would be charged by an 

<PAGE>

BPF
Regency Bancorp                                                    June 3, 1998

                                                                    Page 7 of 7

     independent provider of such services with the same type, level and 
     quality of expertise.  The Company acknowledges that the services 
     contemplated herein will meet legitimate needs of the Company and
     that it is in the best interests of the Company to obtain such services. 

15.  After closing of a Transaction, Belle Plaine shall have the right to place
     advertisements in financial and other newspapers and other newspapers and
     journals at its own expense describing its services to the Company under
     this agreement, provided that Belle Plaine shall have submitted a copy of
     any such proposed advertisements to the Company for its prior approval,
     which approval shall not be unreasonably withheld or delayed.

Please confirm that the foregoing is in accordance with your understanding by
signing and returning to us the duplicates of this agreement and the related
indemnification agreement which shall thereupon constitute binding agreements.

                                   Very truly yours,
                 
                                   /s/ William J. Ruh

                                   Belle Plaine Financial, LLC



                                   William J. Ruh
                                   Senior Vice President



Accepted and agreed:

---------------------
on its behalf and on behalf of the Company,
as defined above.

By: /s/ Steven F. Hertel
    --------------------------------

Name: Steven F. Hertel
    --------------------------------

Title: PRES & CEO
    --------------------------------

Date: 7/23/98
    --------------------------------


<PAGE>
 
BPF                                                                  APPENDIX A

     This Appendix A is a part of and is incorporated into that certain 
letter agreement dated June 3, 1998, between Regency Bancorp (the "Company") 
and Belle Plaine Partners, Inc. ("Belle Plaine") (the letter agreement and 
this Appendix A are referred to herein as the "Agreement").  Capitalized 
terms used herein without definition shall have the meanings ascribed to them 
in such letter agreement.

     The Company agrees to indemnify and hold harmless Belle Plaine, any 
affiliates and the respective officers, directors, partners, representatives 
and agents and any other persons controlling Belle Plaine or any of its 
affiliates (Belle Plaine and each such other person or entity each being 
referred to as an "Indemnified Person"), to the fullest extent lawful, from 
and against all claims, liabilities, losses, damages, and expenses, 
(including without limitation and as incurred, reimbursement of all 
reasonable costs of investigating, preparing, pursuing, or defending any such 
claim or action, including fees and expenses of counsel to, and the 
reasonable per diem costs and expenses of personnel of, the Indemnified 
Person, whether or not arising out of pending litigation, governmental 
investigation, arbitration or other alternative dispute resolution, or other 
action or proceeding or threatened litigation, governmental investigation, 
arbitration or other alternative dispute resolution, or other action or 
proceeding) directly or indirectly related to or arising out of, or in 
connection with (i) actions taken or omitted to be taken by the Company, its 
affiliates, employees, directors, partners, representatives or agents in 
connection with any Transaction or activities contemplated by this Agreement; 
(ii) actions taken or omitted to be taken by any Indemnified Person pursuant 
to the terms of, or in connection with services rendered pursuant to, this 
Agreement, provided that in the case of this subsection (ii), the Company 
shall not be responsible for any claim, liability, loss, damage or expense 
arising primarily out of or based primarily upon the willful misconduct or 
gross negligence (as determined by the judgment of a court of competent 
jurisdiction, no longer subject to appeal or further review) of or by such 
Indemnified Person; and (iii) any untrue statement or alleged untrue 
statement of a material fact contained in any information provided to Belle 
Plaine by the Company under the Agreement or any omission or alleged omission 
to state a material fact necessary to make the statements therein not 
misleading (other than untrue statements or alleged untrue statements in, or 
omissions or alleged omissions from, information relating to an Indemnified 
Person furnished in writing by or on behalf of such Indemnified Person 
expressly for use by the Company).  If multiple claims are brought against an 
Indemnified Person in an arbitration with respect to at least one of which 
indemnification is permitted under applicable law and provided for under this 
Agreement, the Company agrees that any arbitration award shall be 
conclusively deemed to be based on claims as to which indemnification is 
permitted and provided for, except to the extent that the arbitration award 
expressly states that the award, or any portion thereof, is based solely on a 
claim as to which indemnification is not available.

     If the indemnification provided for herein is unavailable to an Indemnified
Person in respect of any claims, liabilities, losses, damages or expenses, then
the Company, in lieu of indemnifying such Indemnified Person, shall contribute
to the amount paid or payable by such Indemnified Person as a result of such
claims, liabilities, losses, damages or expenses (i) in such proportion as is
appropriate to reflect the relative benefits received by the Company on the one
hand and the Indemnified Person on the other, as well as any other relevant
equitable considerations. It is further agreed that the relative benefits to the
Company on the one hand and Belle Plaine on the other hand with respect to the
services rendered under this Agreement shall be deemed to be in the same
proportion as (i) the aggregate Transaction Value bears to (ii) the fees
actually paid to Belle Plaine with respect to the services provided pursuant to
this Agreement in connection with the Transaction.  The Company also agrees that
no Indemnified Person shall have any liability to the Company for or in
connection with this Agreement and the engagement of Belle Plaine hereunder,
except for such 

<PAGE>

BPF

claims, liabilities, losses, damages, or expenses incurred by the Company to 
the extent they are appropriately judicially determined (without possibility 
of appeal or review) to have resulted primarily from such Indemnified 
Person's willful misconduct or gross negligence, and the Company agrees that 
in no event shall the Indemnified Persons be required to contribute an amount 
in the aggregate greater than the fees actually received by Belle Plaine for 
its services performed under this Agreement.

     If any action or other proceeding or investigation is commenced as to 
which an Indemnified Person demands indemnification, the Indemnified Person 
shall have the right to retain counsel of its own choice to represent it, the 
Company shall pay the reasonable fees and expenses of such counsel, and such 
counsel shall to the extent consistent with its professional responsibilities 
cooperate with the Company and any counsel designated by the Company, 
provided, that in no event shall the Company be required to pay fees and 
expenses under this indemnity for more than one firm of attorneys for the 
Indemnified Person in any jurisdiction in any one legal action or group or 
related legal actions. The Company shall be liable as provided herein for any 
settlement of any claim against Belle Plaine or any Indemnified Person made 
with the Company's written consent, which consent shall not be unreasonably 
withheld.  The Company agrees that it will not, without the prior written 
consent of Belle Plaine, settle or compromise or consent to the entry of any 
judgment in any pending or threatened claim, action or proceeding relating to 
the matters contemplated by Belle Plaine's engagement (whether or not any 
Indemnified Person is a party thereto) unless such settlement, compromise or 
consent includes an unconditional release of Belle Plaine and each other 
Indemnified Person from all liability arising or that may arise out of such 
claim, action, or proceeding.

     The indemnity and contribution obligations of the Company set forth 
herein shall be in addition to any liability or obligation the Company may 
otherwise have to any Indemnified Person.  The Company hereby consents to 
personal jurisdiction, service and venue in any court in which any claim 
which is subject to this Agreement is brought against Belle Plaine or any 
other Indemnified Person.

     It is understood that, in addition to Belle Plaine's engagement pursuant 
to this Agreement, Belle Plaine may also be engaged to act for the Company in 
one or more additional capacities, and that the terms of such additional 
engagements may be embodied in one or more separate written agreements.  The 
provisions of this Appendix A shall apply to any such separate agreements, 
any modification so this Agreement, and any modifications of such separate 
agreements, and the provisions of this Appendix A shall remain in full force 
and effect following the completion, expiration or termination of this 
Agreement or such additional agreements or modifications of any of the 
foregoing.