As Filed with the Securities and Exchange Commission on December 8, 2003

REGISTRATION NO. 333-74844

811-05846

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SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM N-4

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

POST-EFFECTIVE AMENDMENT NO. 6

AND

AMENDMENT NO. 55

TO

REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY ACT OF 1940

SUN LIFE OF CANADA (U.S.) VARIABLE ACCOUNT F

(Exact Name of Registrant)

SUN LIFE ASSURANCE COMPANY OF CANADA (U.S.)

(Name of Depositor)

ONE SUN LIFE EXECUTIVE PARK

WELLESLEY HILLS, MASSACHUSETTS 02481

(Address of Depositor's Principal Executive Offices)

DEPOSITOR'S TELEPHONE NUMBER: (781) 237-6030

EDWARD M. SHEA, ASSISTANT VICE PRESIDENT AND SENIOR COUNSEL

SUN LIFE ASSURANCE COMPANY OF CANADA (U.S.)

ONE SUN LIFE EXECUTIVE PARK

112 WORCESTER STREET

WELLESLEY HILLS, MASSACHUSETTS 02481

(Name and Address of Agent for Service)

COPIES OF COMMUNICATIONS TO:

JOAN E. BOROS, ESQ.

JORDEN BURT LLP

1025 THOMAS JEFFERSON STREET, N.W.

SUITE 400 EAST

WASHINGTON, D.C. 20007-0805

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IT IS PROPOSED THAT THIS FILING WILL BECOME EFFECTIVE (check appropriate box)

/X/ IMMEDIATELY UPON FILING PURSUANT TO PARAGRAPH (b) OF RULE 485

/ / ON (Date)PURSUANT TO PARAGRAPH (b) OF RULE 485

/ / 60 DAYS AFTER FILING PURSUANT TO PARAGRAPH (a) OF RULE 485

/ / ON (DATE) PURSUANT TO PARAGRAPH (a)(1) OF RULE 485

This Amendment No.6 to the Registration Statement on Form N-4 (File Nos. 333-74844, 811-05846) is being filed pursuant to Rule 485 (b) under the Securities Act of 1933, as amended, in order to add a supplement to the prospectus. This Amendment does not otherwise delete, amend, or supersede any prospectus, statement of additional information, exhibit, or other information contained in Post-Effective Amendment No. 5 to the Registration Statement.

PART A

SUPPLEMENT DATED DECEMBER 8, 2003

TO

PROSPECTUSES DATED MAY 1, 2003
FOR
MFS REGATTA MASTERS FLEX

ISSUED BY SUN LIFE ASSURANCE COMPANY OF CANADA (U.S.)
SUN LIFE OF CANADA (U.S.) VARIABLE ACCOUNT F

Nine new Funds Sub-Accounts are being made available through to the Contracts offered by means of the Prospectus. In addition, several funds Sub-Accounts are being closed to future investment by Contracts purchased on or after February 2, 2004. The list of variable investment options, on the first page of the prospectus, is hereby revised as follows:

Large-Cap Value Equity Funds	Mid-Cap Value Equity Funds (continued)
Franklin Templeton VIP Trust Templeton Foreign	Sun Capital Real Estate Fund(R) **
Securities Fund, Class 2	Sun Capital Real Estate Fund(R) - S Class*
Franklin Templeton VIP Trust Templeton Growth	Mid-Cap Blend Equity Funds
Securities Fund - Class 2*	Sun CapitalSM All Cap Fund - S Class*
Lord Abbett Series Fund All Value Portfolio*	Mid-Cap Growth Equity Funds
Lord Abbett Series Fund Growth & Income Portfolio	Lord Abbett Series Fund Growth Opportunities
MFS/ Sun Life Strategic Value - S Class**	Portfolio*
MFS/Sun Life Total Return - S Class	MFS/ Sun Life Mid Cap Growth - S Class**
MFS/ Sun Life Utilities - S Class	Small-Cap Value Equity Funds
MFS/ Sun Life Value - S Class	Franklin Templeton VIP Trust Franklin Small Cap
Large-Cap Blend Equity Funds	Value Securities Fund, Class 2
MFS/ Sun Life Capital Opportunities - S Class	Small-Cap Blend Funds
MFS/ Sun Life Massachusetts Investors Trust	Oppenheimer Main Street Small Cap Fund/VA
- S Class	- Service Shares
MFS/ Sun Life Research - S Class	Small-Cap Growth Equity Funds
MFS/ Sun Life Research International - S Class	MFS/ Sun Life New Discovery - S Class
Oppenheimer Capital Appreciation Fund/VA -	High-Quality Short-Term Bond Funds
Service Shares	PIMCO VIT Low Duration Portfolio*
Oppenheimer Main Street Fund/VA - Service Shares	PIMCO VIT Real Return Portfolio
Large-Cap Growth Equity Funds	High-Quality Intermediate-Term Bond Funds
MFS/ Sun Life Capital Appreciation - S Class**	MFS/ Sun Life Government Securities - S Class
MFS/ Sun Life Emerging Growth - S Class	Sun Capital Investment Grade Bond Fund(R)
MFS/ Sun Life Global Growth - S Class**	- S Class*
MFS/ Sun Life Massachusetts Investors Growth	PIMCO VIT Total Return Portfolio
Stock - S Class	Medium-Quality Intermediate-Term Bond Funds
MFS/ Sun Life Strategic Growth - S Class	MFS/ Sun Life Bond - S Class**
Oppenheimer Global Securities Fund/VA*	MFS/ Sun Life Strategic Income - S Class**
Mid-Cap Value Equity Funds	Low-Quality Short-Term Bond Fund
Franklin Templeton VIP Trust Mutual	MFS/ Sun Life High Yield - S Class
Shares Securities Fund, Class 2	Low-Quality Intermediate-Term Bond Fund
Lord Abbett Series Fund Mid Cap Value Portfolio	PIMCO VIT Emerging Markets Bond Portfolio*
MFS/ Sun Life Mid Cap Value - S Class**	Money Market Fund
	MFS/ Sun Life Money Market - S Class

*   Available for investment beginning on February 2, 20043.

** Not available for investment on Contracts purchased on or after February 2, 20043.

In addition, effective February 2, 2004, the name of the MFS Regatta Masters Flex Prospectus will be changed to "Sun Life Financial Masters Flex." All reference to "MFS Regatta Masters Flex" throughout the prospectus will therefore be changed to "Sun Life Financial Masters Flex."

PART C

OTHER INFORMATION

Item 24. FINANCIAL STATEMENTS AND EXHIBITS

(a)	The following Financial Statements are incorporated by reference to Post-Effective Amendment No. 5 to the Registration Statement on Form N-4 (File No. 333-74844), filed on April 28, 2003:
	A.	Condensed Financial Information - Accumulation Unit Values
		(Part A)
	B.	Financial Statements of the Depositor (Part B)
		Audited:
		1.	Consolidated Statements of Income, Years Ended December 31, 2002, 2001 and 2000;
		2.	Consolidated Balance Sheets, December 31, 2002 and 2001,
		3.	Consolidated Statements of Comprehensive Income, Years Ended December 31, 2002, 2001 and 2000
		4.	Consolidated Statements of Stockholder's Equity, Years Ended December 31, 2002, 2001 and 2000;
		5.	Consolidated Statements of Cash Flows, Years Ended December 31, 2002, 2001 and 2000;
		6.	Notes to Consolidated Financial Statements; and
		7.	Independent Auditors' Report.
	C.	Financial Statements of the Registrant (Part B)
		1.	Statement of Condition, December 31, 2002;
		2.	Statement of Operations, Year Ended December 31, 2002;
		3.	Statements of Changes in Net Assets, Years Ended December 31, 2002 and December 31, 2001;
		4.	Notes to Financial Statements; and
		5.	Independent Auditors' Report.

(b) The following Exhibits are incorporated in the Registration Statement by reference unless otherwise indicated:

(1)	Resolution of Board of Directors of the Depositor dated December 3, 1985 authorizing the establishment of the Registrant (Incorporated herein by reference to Exhibit 1 to Registrant's Registration Statement on Form N-4, File No. 333-37907, filed on October 14, 1997);
(2)	Not Applicable;
(3)(a)	Marketing Services Agreement between Sun Life Assurance Company of Canada (U.S.), Sun Life of Canada (U.S.) Distributors, Inc. and Clarendon Insurance Agency, Inc. (Incorporated herein by reference to Exhibit 3(a) to Pre-Effective Amendment No. 1 to Registrant's Registration Statement on Form N-4, File No. 333-37907, filed on January 16, 1998);
(3)(b)(i)	Specimen Sales Operations and General Agent Agreement (Incorporated herein by reference to Exhibit 3(b)(i) to Pre-Effective Amendment No. 1 to Registrant's Registration Statement on Form N-4, File No. 333-37907, filed on January 16, 1998);
(3)(b)(ii)	Specimen Broker-Dealer Supervisory and Service Agreement (Incorporated herein by reference to Exhibit 3(b)(ii) to Pre-Effective Amendment No. 1 to Registrant's Registration Statement on Form N-4, File No. 333-37907, filed on January 16, 1998);
(3)(b)(iii)	Specimen Registered Representatives Agent Agreement (Incorporated herein by reference to Exhibit 3(b)(iii) to Pre-Effective Amendment No. 1 to Registrant's Registration Statement on Form N-4, File No. 333-37907, filed on January 16, 1998);
(4)(a)	Specimen Flexible Payment Combination Fixed/Variable Group Annuity Contract (Filed as Exhibit 4(a) to Pre-Effective Amendment No. 1 to the Registration Statement on Form N-4, file 333-74884, filed on February 14, 2002);
(4)(b)	Specimen Certificate to be issued in connection with Contract filed as Exhibit 4(a) (Incorporated by reference to Exhibit 4(b) to Registrant's Registration Statement on Form N-4, File No. 333-74844, filed on December 10, 2001);
(4)(c)	Specimen Flexible Payment Combination Fixed/Variable Individual Annuity Contract (Filed as Exhibit 4(c) to Pre-Effective Amendment No. 1 to the Registration Statement on Form N-4, file 333-74884, filed on February 14, 2002);
(5)(a)	Specimen Application to be used with Contract filed as Exhibit 4(a) (Filed as Exhibit 5(a) to Pre-Effective Amendment No. 1 to the Registration Statement on Form N-4, file 333-74884, filed on February 14, 2002);
(5)(b)	Specimen Application to be used with Certificate filed as Exhibit 4(b) and Contract filed as Exhibit 4(c) (Filed as Exhibit 5(b) to Pre-Effective Amendment No. 1 to the Registration Statement on Form N-4, file 333-74884, filed on February 14, 2002);
(6)(a)	Certificate of Incorporation and By-laws of the Depositor (Incorporated herein by reference to Exhibits 3(a) and 3(b), respectively, to Depositor's Registration Statement on Form S-1, File No. 333-37907, filed on October 14, 1997);
(6)(b)	By-Laws of the Depositor, as amended effective as of January 1, 2000 (Filed as Exhibit 6(b) to Pre-Effective Amendment No. 1 to Registrant's Registration Statement on Form N-4, File No. 333-05846, filed on June 9, 2000);
(7)	Not Applicable;
(8)(a)	Participation Agreement by and between The Alger American Fund, the Depositor, and Fred Alger and Company, Incorporated (Filed as Exhibit 8(a) to Post-Effective Amendment No. 13 to Registrant's Registration Statement on Form N-4, File No. 33-41628, filed on April 23, 1999);
(8)(b)(i)	Participation Agreement dated February 17, 1998 by and between Goldman Sachs Variable Insurance Trust, Goldman Sachs & Co. and the Depositor (Filed as Exhibit 8(b)(i) to Post-Effective Amendment No. 13 to Registrant's Registration Statement on Form N-4, File No. 33-41628, filed on April 23, 1999);
(8)(b)(ii)	Amendment No. 1 dated December 14, 1998 to Participation Agreement filed as Exhibit 8(b)(i) (Filed as Exhibit 8(b)(ii) to Post-Effective Amendment No. 13 to Registrant's Registration Statement on Form N-4, File No. 33-41628, filed on April 23, 1999);
(8)(b)(iii)	Amendment No. 2 dated as of March 15, 1999 to Participation Agreement filed as Exhibit 8(b)(i) (Filed as Exhibit 8(b)(iii) to Post-Effective Amendment No. 13 to Registrant's Registration Statement on Form N-4, File No. 33-41628, filed on April 23, 1999);
(8)(c)	Participation Agreement dated February 17, 1998 by and among MFS/Sun Life Services Trust, the Depositor and Massachusetts Financial Services Company (Filed as Exhibit 8(d) to Post-Effective Amendment No. 13 to Registrant's Registration Statement on Form N-4, File No. 33-41628, filed on April 23, 1999);
(8)(d)	Participation Agreement dated February 17, 1998 by and among the Depositor, AIM Variable Insurance Funds, Inc., AIM Distributors, Inc., and Clarendon Insurance Agency, Inc. (Filed as Exhibit 8(g) to Post-Effective Amendment No. 1 to Registrant's Registration Statement on Form N-4, File No. 333-82957, filed on February 3, 2000);
(8)(e)	Participation Agreement dated August 18, 1999 by and among the Depositor, Sun Capital Advisers Trust and Sun Capital Advisers, Inc. (Filed as Exhibit 8(h) to Post-Effective Amendment No. 1 to Registrant's Registration Statement on Form N-4, File No. 333-82957, filed on February 3, 2000);
(8)(f)	Participation Agreement dated April 30, 2001 by and among Rydex Variable Trust, Rydex Distributors, Inc., and Sun Life Assurance Company of Canada (U.S.). (Incorporated herein by reference to Post-Effective Amendment No. 7 to the Registration Statement on Form N-4 File No. 333-82957, filed July 27, 2001);
(8)(g)	Participation Agreement dated April 15, 2001 by and among Sun Life Assurance Company of Canada (U.S.), INVESCO Variable Investment Funds, Inc., INVESCO Funds Group Inc., and INVESCO Distributors, Inc. (Incorporated herein by reference to Post-Effective Amendment No. 7 to the Registration Statement on Form N-4 File No. 333-82957, filed July 27, 2001);
(8)(h)(i)	Participation Agreement dated December 1, 1996 by and among Sun Life Assurance Company of Canada (U.S.), Variable Insurance Products Funds, and Fidelity Distributors Corporation. (Incorporated herein by reference to Pre-Effective Amendment No. 1 to the Registration Statement on Form S-6 File No. 333-13087, filed January 1, 1997);
(8)(h)(ii)	Amendment No. 1 dated May 1, 2001 to the Participation Agreement by and among Sun Life Assurance Company of Canada (U.S.), Variable Insurance Products Funds, and Fidelity Distributors Corporation. (Incorporated herein by reference to Post-Effective Amendment No. 7 to the Registration Statement on Form N-4 File No. 333-82957, filed July 27, 2001);
(8)(i)	Participation Agreement dated May 1, 2001 by and among Sun Life Assurance Company of Canada (U.S.), the Depositor, Alliance Capital Management L.P., and Alliance Fund Distributors, Inc. (Incorporated herein by reference to Post-Effective Amendment No. 7 to the Registration Statement on Form N-4 File No. 333-82957, filed July 27, 2001.;
(8)(j)	Participation Agreement dated February 17, 1998 by and among Sun Life Assurance Company of Canada (U.S.), Lord Abbett Series Fund, Inc. and Lord, Abbett & Co. (To be Filed by Amendment);
(8)(k)	Participation Agreement (Incorporated by reference to Exhibit 8(k) to Registrant's Registration Statement on Form N-4, File No. 333-74844, filed on December 10, 2001);
(9)	Opinion of Counsel (Incorporated by reference to Exhibit 9 to Registrant's Registration Statement on Form N-4, File No. 333-74844, filed on December 10, 2001);
(10)(a)	Consent of Independent Auditors (Incorporated by reference to Post-Effective Amendment No. 5 to the Registration Statement on Form N-4 (File No. 333-74844), filed on April 28, 2003);
(10)(b)	Representation of Counsel Pursuant to Rule 485(b)*;
(11)	Financial Statement Schedules I and VI (Incorporated herein by reference to the Depositor's Form 10-K Annual Report for the fiscal year ended December 31, 1999, filed on March 22, 2000);
(12)	Not Applicable;
(13)	Schedule for Computation of Performance Quotations (Incorporated by reference to Exhibit 13 to Post-Effective Amendment No. 10 to Registrant's Registration Statement on Form N-4, File No. 33-41628, filed on April 29, 1998);
(14)	Not Applicable;
(15)	Powers of Attorney (Incorporated by reference from Exhibit 15 to Post-Effective Amendment No. 3 to the Registration Statement on Form N-4, File No. 333-30844, filed on February 9, 2001);
(16)	Organizational Chart (Incorporated by reference to Exhibit 16 to Pre-Effective Amendment No. 1 to the Registration Statement of the Registrant on Form N-4, File Nos. 333-107983, 811-04440, filed on October 31, 2003.)

* Filed herewith

Item 25. DIRECTORS AND OFFICERS OF THE DEPOSITOR

Name and	Principal Positions and Officers
Business Address	With Depositor
Donald A. Stewart	Director
150 King Street West
Toronto, Ontario
Canada M5H 1J9
C. James Prieur	Chairman and Director
150 King Street West
Toronto, Ontario
Canada M5H 1J9
Robert C. Salipante	President and Director
One Sun Life Executive Park
Wellesley Hills, MA 02481
David D. Horn	Director
257 Lake Street
P.O. Box 24
New Vineyard, ME 04956
James A. McNulty, III	Director
12 Wild Holly Lane
Medfield, MA 02052
S. Caesar Raboy	Director
220 Boylston Street
Boston, MA 02110
William W. Stinson	Director
1001 13th Avenue S.W.
Calgary, Alberta
Canada T2R 0L5
James C. Baillie	Director
Torys LLP
Suite 3000, 79 Wellington Street West
Box 270, TD Centre
Toronto, Ontario MSK 1N2
Paul W. Derksen	Director
150 King Street West
Toronto, Ontario
Canada M5H 1J9
David K. Stevenson	Director
359 Grove Street
Needham, MA 02492
James M.A. Anderson	Vice President, Investments
One Sun Life Executive Park
Wellesley Hills, MA 02481
Nancy L. Conlin	Vice President and Chief Counsel
One Sun Life Executive Park
Wellesley Hills, MA 02481
Mark W. DeTora	Vice President, Individual Insurance
One Sun Life Executive Park
Wellesley Hills, MA 02481
Robert P. Vrolyk	Vice President and Actuary
One Sun Life Executive Park
Wellesley Hills, MA 02481
Ellen B. King	Assistant Vice President and Senior Counsel and
One Sun Life Executive Park	Secretary
Wellesley Hills, MA 02481
Philip K. Polkinghorn	Vice President, Retirement Products and Services
112 Worcester Street
Wellesley Hills, MA 02481
Gary Corsi	Vice President & Chief Financial Officer & Treasurer
One Sun Life Executive Park
Wellesley Hills, MA 02481
James R. Smith	Vice President & Chief Information Officer
One Sun Life Executive Park
Wellesley Hills, MA 02481
Janet V. Whitehouse	Vice President, Human Resources and
One Sun Life Executive Park	Administrative Services
Wellesley Hills, MA 02481

Item 26. PERSONS CONTROLLED BY OR UNDER COMMON CONTROL WITH THE DEPOSITOR OR REGISTRANT

No person is directly or indirectly controlled by the Registrant. The Registrant is a separate account of Sun Life Assurance Company of Canada (U.S.), a wholly-owned subsidiary of Sun Life of Canada (U.S.) Holdings, Inc., a wholly-owned subsidiary of Sun Life Assurance Company of Canada - U.S. Operations Holdings, Inc., which is in turn a wholly-owned subsidiary of Sun Life Assurance Company of Canada.

The organization chart of Sun Life Assurance Company of Canada is filed as Exhibit 16 to Pre-Effective Amendment No. 1 to the Registration Statement of the Registrant on Form N-4, File Nos. 333-107983, 811-04440, filed on October 31, 2003.

None of the companies listed in such Exhibit 16 is a subsidiary of the Registrant; therefore, the only financial statements being filed are those of Sun Life Assurance Company of Canada (U.S.).

Item 27. NUMBER OF CONTRACT OWNERS

As of December 4, 2003, there were 1,169 qualified and 1,207 non-qualified Contracts issued by the Depositor with respect to the securities registered pursuant to this Registration Statement.

Item 28. INDEMNIFICATION

Pursuant to Section 145 of the Delaware Corporation Law, Article 8 of the By-laws of Sun Life Assurance Company of Canada (U.S.), as amended effective as of January 1, 2000 (a copy of which was filed as Exhibit 6(b) to Pre-Effective Amendment No. 1 to Registrant's Registration Statement on Form N-4, File No. 333-30844) provides for the indemnification of directors, officers and employees of Sun Life Assurance Company of Canada (U.S.).

Insofar as indemnification for liability arising under the Securities Act of 1933 may be permitted to directors, officers and controlling persons of Sun Life Assurance Company of Canada (U.S.) pursuant to the certificate of incorporation, by-laws, or otherwise, Sun Life (U.S.) has been advised that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by Sun Life (U.S.) of expenses incurred or paid by a director, officer, controlling person of Sun Life (U.S.) in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, Sun Life (U.S.) will submit to a court of appropriate jurisdiction the question whether such indemnification by them is against public policy as expressed in the Act, unless in the opinion of their counsel the matter has been settled by controlling precedent, and will be governed by the final adjudication of such issue.

Item 29. PRINCIPAL UNDERWRITERS

(a) Clarendon Insurance Agency, Inc., a wholly-owned subsidiary of Sun Life Assurance Company of Canada (U.S.), acts as general distributor for the Registrant, Sun Life of Canada (U.S.) Variable Accounts C, D, E, G, H and I, Sun Life (N.Y.) Variable Accounts A, B and C, and Money Market Variable Account, High Yield Variable Account, Capital Appreciation Variable Account, Government Securities Variable Account, World Governments Variable Account, Total Return Variable Account, and Managed Sectors Variable Account.

Name and Principal	Positions and Officers
Business Address*	with Underwriter
Jane P. Wolak	President
Jane F. Jette	Financial/Operations Principal and Treasurer
James M.A. Anderson	Director
Gary Corsi	Director
Ellen B. King	Clerk
Norton A. Goss, II	Director, Vice President & Chief Compliance Officer
Michael L. Gentile	Vice President
John E. Coleman	Vice President
Nancy C. Atherton	Assistant Vice President and Tax Officer
Imants Saksons	Vice President

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* The principal business address of all directors and officers of the principal underwriter, except Ms. Wolak, is One Sun Life Executive Park, Wellesley Hills, Massachusetts 02481. The principal business address of Ms. Wolak is 112 Worcester Street, Wellesley Hills, MA 02481.

(b) Inapplicable.

Item 30. LOCATION OF ACCOUNTS AND RECORDS

Accounts, books and other documents required to be maintained by Section 31(a) of the Investment Company Act of 1940 and the Rules promulgated thereunder are maintained, in whole or in part, by Sun Life Assurance Company of Canada (U.S.) at its offices at One Sun Life Executive Park, Wellesley Hills, Massachusetts 02481 or at the offices of Clarendon Insurance Agency, Inc., at One Sun Life Executive Park, Wellesley Hills, Massachusetts 02481.

Item 31. MANAGEMENT SERVICES

Not Applicable.

Item 32. UNDERTAKINGS

The Registrant hereby undertakes:

(a)	To file a post-effective amendment to this Registration Statement as frequently as is necessary to ensure that the audited financial statements in the Registration Statement are never more than 16 months old for so long as payments under the variable annuity Contracts may be accepted;
(b)	To include either (1) as part of any application to purchase a Contract offered by the prospectus, a space that an Applicant can check to request a Statement of Additional Information, or (2) a post card or similar written communication affixed to or included in the prospectus that the Applicant can remove to send for a Statement of Additional Information;
(c)	To deliver any Statement of Additional Information and any financial statements required to be made available under SEC Form N-4 promptly upon written or oral request.
(d)	Representation with respect to Section 26(e) of the Investment Company Act of 1940: Sun Life Assurance Company of Canada (U.S.) represents that the fees and charges deducted under the Contracts, in the aggregate, are reasonable in relation to the services rendered, the expenses expected to be incurred, and the risks assumed by the insurance company.
	The Registrant is relying on the no-action letter issued by the Division of Investment Management of the Securities and Exchange Commission to American Council of Life Insurance, Ref. No. IP-6-88, dated November 28, 1988, the requirements for which have been complied with by the Registrant.

SIGNATURES

As required by the Securities Act of 1933 and the Investment Company Act of 1940, the Registrant certifies that it meets all of the requirements of Securities Act Rule 485(b) for effectiveness of this Post-Effective Amendment to the Registration Statement and has caused this Post-Effective Amendment to the Registration Statement to be signed on its behalf, in the Town of Wellesley Hills, and Commonwealth of Massachusetts on this 8th day of December, 2003.

SUN LIFE OF CANADA (U.S.) VARIABLE ACCOUNT F

(Registrant)

SUN LIFE ASSURANCE COMPANY OF CANADA (U.S.)

(Depositor)

By: /s/ ROBERT C. SALIPANTE

Robert C. Salipante

President and Director

Attest:	/s/ EDWARD M. SHEA
	Edward M. Shea
	Assistant Vice President & Senior Counsel

As required by the Securities Act of 1933, this Registration Statement has been signed below by the following persons in the capacities with the Depositor, Sun Life Assurance Company of Canada (U.S.), and on the dates indicated.

SIGNATURE	TITLE	DATE
/s/ ROBERT C. SALIPANTE	President and Director	December 8, 2003
Robert C. Salipante	(Principal Executive Officer)
/s/ GARY CORSI	Vice President & Chief Financial	December 8, 2003
Gary Corsi	Officer & Treasurer
	(Principal Financial and Accounting Officer)
/s/ EDWARD M. SHEA	Attorney-in-Fact for:	December 8, 2003
Edward M. Shea	C. James Prieur, Chairman and Director
	Donald A. Stewart, Director
	David D. Horn, Director
	James A. McNulty, III, Director
	S. Caesar Raboy, Director
	Paul W. Derksen, Director
	William W. Stinson, Director

EXHIBIT INDEX

Item:
(10)(b)	Representation of Counsel Pursuant to Rule 485(b)