Radian Group Inc. sold its unit that insures municipal bonds to Assured Guaranty Ltd. for net proceeds of $789 million, the Philadelphia company said.

The sale of Radian Asset Assurance Inc. will help Radian's primary businness, a private mortgage insurer, meet new financial requirements for mortgage insurers that are expected to go into effect at the end of this year.

Counting proceeds from the Asset Assurance sale, Radian said in December that it expected to have a net shortfall of $400 million when the new rules go into effect on Dec. 31.

But insurers have time to meet the new standard, and Radian said it expected to be in compliance by June 30, 2017, the end of the transition period.