NEW YORK AP-Major banks are stepping up their efforts to curtail losses from souring mortgages, with Citigroup Inc. becoming the latest institution to adopt initiatives aimed at helping at-risk borrowers remain in their homes.

With defaults mounting, lenders including JPMorgan Chase & Co. and Bank of America Corp. have become more aggressive about modifications to mortgage agreements. The government is also working on an ambitious plan to help around 3 million borrowers avoid foreclosure, but details have yet to be released.