FOR IMMEDIATE RELEASE                                       CONTACT:
                                                            James C. Rowan, Jr.
                                                            Office: 860-722-5180


HSB GROUP, INC.
ANNOUNCES SALE OF $110M CAPITAL SECURITIES

HARTFORD,  CT, July 10, 1997 -- HSB Group, Inc.  (NYSE-HSB)  announced today the
sale of $110 million of 30-year Floating Rate Capital  Securities  issued by HSB
Capital I, a Delaware statutory business trust created by HSB Group, Inc.

The  securities  were sold in a private  placement  under Rule 144A to qualified
institutional investors and have not been registered under the Securities Act of
1933,  as  amended.  The  Capital  Securities  may not be offered or sold in the
United  States  absent   registration  or  an  applicable   exemption  from  the
registration requirements of the Securities Act and applicable state laws.

The company  said it expects to use the net  proceeds  from the sale for general
corporate purposes, which may include repurchases of the company's common stock,
funding investments in, or extensions of credit to, the company's  subsidiaries,
repayment of maturing  obligations,  and financing possible future acquisitions.
Pending  such use,  the company may  temporarily  invest the proceeds or may use
them to reduce short-term indebtedness.

HSB Group,  Inc.  is the parent of The  Hartford  Steam  Boiler  Inspection  and
Insurance  Company,  which has  specialized in loss  prevention and loss control
engineering since 1866 and today is the largest provider of equipment  breakdown
insurance in the world.