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[RADIAN LETTERHEAD]




                                              CONTACT:
                                              William Campbell, 212 254.6670

                          AMERIN/CMAC MERGER COMPLETE;
                 MERGED COMPANY, RADIAN, NOW #2 MORTGAGE INSURER

         PHILADELPHIA, Pa., June 9, 1999 -- The stockholders of Amerin
Corporation (NASDAQ:AMRN) and CMAC Investment Corporation (NYSE: CMT) today
approved the merger of their two companies. Following the stockholder approval,
the companies completed the direct merger of Amerin into CMAC.

         The combined entity will operate under the name Radian Group Inc. and
trade on the New York Stock Exchange under the symbol "RDN." Radian Group Inc.
is the parent of Radian Guaranty Inc., which is the nation's second largest
mortgage insurer. Radian has:

         -        An 18.3% first-quarter market share

         -        Assets of $1.6 billion and equity of $1.0 billion

         -        $85 billion of insurance in force

         -        First quarter earnings of $37.4 million

         -        3,500 mortgage lender clients, including 26 of the top 30

         -        838 employees in 28 offices nationwide

         Frank P. Filipps, chairman and chief executive officer of Radian, said:
"This merger creates a larger, stronger company capable of delivering greater
value to our stockholders and our clients. Radian has the creative and financial
strength to accelerate the transformation of mortgage insurance, making these MI
products more efficient and profitable for lenders, and more attractive to
borrowers. We want to thank our stockholders, our employees and the clients of
both Amerin and CMAC for the confidence they have shown in the potential of
Radian. We intend to keep on earning it."


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         In the merger, Amerin stockholders receive .5333 shares of Radian
common stock for each Amerin share. Taking into account the effect of the
merger, there are approximately 36.9 million shares of Radian common stock
outstanding.

         Radian Group Inc. is the parent company of Radian Guaranty Inc. The
company provides private mortgage insurance and risk management services to
mortgage lenders nationwide; these services increase homeownership opportunities
by helping people to buy homes with down payments of less than 20 percent.
Private mortgage insurance protects lenders from default-related losses on
residential first mortgages and facilitates the sale of low-down-payment
mortgage loans in the secondary market.

         The following is a "Safe Harbor" Statement under the Private Securities
Litigation Reform Act of 1995:

         The statements contained in this release that are not historical facts
are forward-looking statements. Actual results may differ materially from those
projected in the forward-looking statements. These forward-looking statements
involve risks and uncertainties, including but not limited to, the following
risks: that interest rates may increase rather than remain stable or decrease;
that housing demand may decrease for any number of reasons, including changes in
interest rates, adverse economic conditions, or other reasons; that Radian's
market share may decrease as a result of changes in underwriting criteria by
Radian or its competitors, or other reasons; and changes in the performance of
the financial markets, in the demand for and market acceptance of Radian
products, increased competition from government programs and the use of
substitutes for mortgage insurance, and in general conditions. Investors are
also directed to other risks discussed in documents filed by Radian with the
Securities and Exchange Commission.

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