The “strategic alliances” that most top mortgage lenders formed with Fannie Mae and Freddie Mac several years ago have evolved to a more balanced approach. According to Home Mortgage Disclosure Act data, 17 of the 50 largest sellers of loans to the two government-sponsored enterprises split their sales in 2001 so that each GSE got at least 10 percent of the total. In 2002, that number increased to 22, according to an analysis of