Citigroup Inc, the fourth-biggest US bank by market value, plans to stem foreclosures as the firm modifies about $20 billion in mortgages, following similar moves by its largest rivals.

Citigroup will reach out to 500,000 homeowners in the next six months who may be at risk of falling behind on mortgage payments, the New York-based company said in a statement yesterday. The bank has helped about 370,000 people, or $35 billion in mortgages, avoid foreclosure since 2007.

Congress has been urging financial-services companies to work with borrowers after foreclosures rose to the highest on record in the third quarter. JPMorgan Chase & Co said Oct 31 it will stop foreclosure on some loans as it works to make payments easier on $110 billion of problem mortgages, while Bank of America Corp said it has modified 226,000 loans this year, including those from Countrywide Financial Corp.