<PAGE>
Rule 424(b)(3)
File No. 333-11699
SUPPLEMENT DATED DECEMBER 13, 1999
TO
PROFILE DATED MAY 1, 1999
AND
PROSPECTUS DATED MAY 1, 1999
FOR
MFS REGATTA CLASSIC
VARIABLE AND FIXED ANNUITY
ISSUED BY SUN LIFE ASSURANCE COMPANY OF CANADA (U.S.)
As disclosed in the Prospectus dated May 1, 1999 (the "Prospectus") for
MFS Regatta Classic Variable and Fixed Annuity, our affiliate Massachusetts
Financial Services Company ("MFS") has retained Foreign & Colonial Management
Limited ("FCM") and its subsidiary, Foreign & Colonial Emerging Markets Limited
("FCEM"), as sub-advisers to manage the assets of MFS/Foreign & Colonial
Emerging Markets Equity Series (the "Series"). As disclosed in the prospectus
for the MFS/Sun Life Series Trust that accompanies the Prospectus, the Series
seeks capital appreciation by investing primarily in emerging market securities.
Effective December 1, 1999, MFS assumed all portfolio management
responsibilities for emerging market securities from FCM and FCEM with respect
to the Series, and the sub-investment advisory agreements pursuant to which FCM
and FCEM provided their services to the Series were terminated. All references
to FCM, FCEM and the sub-investment advisory agreements with respect to the
Series contained in the Prospectus are hereby deleted.
Additionally, effective December 1, 1999, the name of the Series as it
appears in the Profile dated May 1, 1999 for MFS Regatta Classic Variable and
Fixed Annuity and in the Prospectus was changed to "Emerging Markets Equity
Series."
THIS SUPPLEMENT IS NOT VALID UNLESS ACCOMPANIED OR PRECEDED BY THE CURRENT
PROSPECTUS OF MFS REGATTA CLASSIC VARIABLE AND FIXED ANNUITY, DATED MAY 1, 1999,
AND THE CURRENT PROSPECTUS OF THE MFS/SUN LIFE SERIES TRUST. THIS SUPPLEMENT AND
THE PROSPECTUSES SHOULD BE READ AND RETAINED FOR FURTHER REFERENCE.
CLASSICSUPP-2 12/99
