Fallen insurer American International Group has withdrawn from the U.S. Climate Action Partnership (USCAP) over questions of the company putting taxpayer money toward its membership in the group, which is lobbying Congress for climate change legislation.

The company, propped up by billions of federal tax dollars in late 2008 to avoid a collapse, was queried over its continued participation in USCAP by Rep. Joe Barton, R-Texas, who is a critic of mandatory greenhouse gas emissions cuts because he's afraid the legislation will hurt the U.S. economy, according to Dow Jones Newswires.

"It is entirely appropriate for AIG to withdraw from USCAP," Barton told the wire service. "American taxpayers now own 80 percent of AIG and they should not have to fund its lobbying efforts to make cap-and-trade a reality."

USCAP is a coalition of corporations and environmental groups with members that include Dow Chemical, Ford Motor Company, PepsiCo, Xerox, Environmental Defense Fund, Shell, Siemens and Johnson and Johnson, among others. Last month, USCAP offered a blueprint for reducing greenhouse gas emissions 80 percent below 2005 levels by 2050, with a federal greenhouse gas cap-and-trade as the centerpiece. AIG joined USCAP in April 2007.

AIG, which could make money from a cap-and-trade through climate change-related insurance products, told Dow Jones through a spokesman it hasn't changed its position on cap-and-trade but it has made a decision to suspend federal lobbying activity.