MBIA Inc. reported a second-quarter non-GAAP combined operating loss of $139 million, compared with operating income of $15 million, in the year-ago quarter.

The GAAP net loss was $1.23 billion, or $9.78 per share, compared with a loss of $27 million, or 20 cents per share, in the second quarter of 2016.

The company took a $1.02 billion charge to net income for the quarter as a provision for income taxes, related to its decision to cease writing new bond insurance business through National Public Finance Guarantee Corp.

The company's combined operating loss for the quarter was partly due to higher losses and loss adjustment expenses at National, primarily due to exposures to Puerto Rico, the company said.

Adjusted book value per share was $26.26 as of June 30, compared with $31.88 as of Dec. 31, 2016.