Stricter lending standards adopted last year by Fannie Mae are beginning to pay off as the mortgage finance giant's "new book" of business is the strongest in a decade, the firm's chief executive said on Wednesday.

Fannie Mae is emphasizing safer, long-term, fixed-rate loans and asking lenders to make loans on homes with better appraisals, to borrowers with better credit and better documentation of income.

"If you take all of these factors together, we're building the strongest book of business we've seen in the last decade," CEO Michael Williams said in remarks prepared for delivery to the group Women in Housing and Finance.