WASHINGTON – The International Monetary Fund cautioned Tuesday that rising government debt has replaced financial industry stress as the biggest threat to the global economy and cut its estimate for asset writedowns by 19 percent.

Banks reduced the value of loans and securities by $2.28 trillion since 2007, two-thirds of which had been realized by the end of 2009, down from the IMF’s October estimate of $2.81 trillion, the fund said Tuesday in its Global Financial Stability Report. About 39 percent of the writedowns were in U.S. banks, 29 percent in the euro area and 20 percent in Britain, the IMF said.

While the global economic recovery has “gained steam” and risks to the financial system have subsided, concerns are rising for sovereign debt issued by advanced countries that bailed out banks, the IMF report said. Governments need “credible, medium-term” plans to reduce deficits and some nations need to do more to revive the flow of credit and boost growth.

“The deterioration of fiscal balances and the rapid accumulation of public debt have altered the global risk profile,” the IMF said. “Vulnerabilities now increasingly emanate from concerns over the sustainability of governments’ balance sheets.”