Fannie working to repay large chunk of rescue.

 Fannie Mae (FNMA.OB) is working on an accounting change that could allow it to repay up to $61.5B of the $88B that it owes to the Treasury. Under the change, Fannie would reclaim tax benefits that were written down after the government took it over in 2008. The return of billions of dollars to the government "could have important repercussions for reform and other housing-finance discussions,"