Aug 8 (Reuters) - U.S. bond insurer MBIA Inc's second-quarter net income rose more than four-fold, helped by a $1.2 billion pre-tax unrealized gains on insured credit derivatives.
MBIA shares rose 6 percent in extended trade. They closed at $8.76 on Wednesday on the New York Stock Exchange.
The company's net income available to common shareholders rose to $581 million, or $2.98 per share, from $137 million, or 68 cents per share, a year earlier.
MBIA's total premiums earned in the U.S. public finance insurance segment rose 23 percent to $130 million.
The company reported an adjusted pre-tax loss of $152 million in the quarter, compared with a profit of $161 million a year earlier.