Bank of America Corp, the largest U.S. bank by assets, reported a second straight quarterly loss, driven by a $2 billion writedown of its mortgage business.

The bank posted a fourth-quarter net loss of $1.2 billion, or 16 cents a share, compared with a loss of $5.2 billion, or 60 cents a share, a year earlier. Last year's results included a one-time Troubled Asset Relief Program-related charge of $4 billion.

Excluding the mortgage business writedown, the bank earned $756 million, or 4 cents per share.

(Reporting by Joe Rauch; editing by John Wallace)