Freddie Mac last year regained some of the ground it lost to rival GSE Fannie Mae during 2003, when inferior performance by Freddie’s MBS cost the company market share. Freddie Mac issued $337 billion in MBS through the first 11 months of 2004. That represents 40.9 percent of the total MBS issued by the two government-sponsored enterprises. It also represented a measurable improvement from the 37.7 percent share of GSE MBS issuance the company recorded…