The US Treasury will sell a $142bn portfolio of mortgage-backed securities acquired during the financial crisis, in the latest withdrawal from government market intervention.

Officials said on Monday they expect to generate $15bn to $20bn in profit from the sale of the securities. The assets were acquired in 2008 and 2009 under authority granted by Congress to fight market turmoil.

The sale, at a rate of up to $10bn a month, will help reduce the federal deficit, but officials stressed its timing was not related to an impending debt limit crunch. The government is expected to breach its debt limit between April 15 and May 31 and needs a reprieve from fiscal hawks in Congress. “The pace that we’ll be unwinding this will not have much impact on the debt ceiling discussions,” a senior Treasury official said.