McDonald's Corp. (MCD) said Wednesday it is studying whether to require its chicken suppliers to use a more humane slaughter method following a proposal by an animal rights group that holds shares in the fast-food chain.

The world's largest fast-food chain is looking into so-called controlled-atmosphere killing, which is already being used by some of its European suppliers, according to its senior director of social responsibility, Bob Langert.

"It has promise, but there is a lot more to learn," Langert said in an interview.

People for the Ethical Treatment of Animals (search), an animal rights group known for its campaigns against fast-food companies, withdrew a shareholder proposal asking McDonald's to look into the alternative slaughter method after the company said it would issue a report on the subject by June of 2005, spokesman Bruce Friedrich said.

PETA, which holds shares of several corporations, has submitted identical proposals to Wal-Mart Stores Inc. (WMT), Wendy's International Inc. (WEN), Safeway Inc. (SWY), and Applebee's International Inc., Friedrich said. A "more comprehensive" proposal had been submitted to Yum Brands Inc. (YUM), parent of the KFC fried-chicken restaurant chain, he added.

PETA contends that chickens supplied to McDonald's and others are sometimes scalded to death while still conscious, a method it deems inhumane. In controlled-atmosphere killing, chickens are put to sleep quickly and painlessly using argon or nitrogen gas, advocates say.

Despite heavy-handed tactics like throwing fake blood at fur-clad celebrities, PETA has had an impact on businesses.

Earlier this year, poultry producer Pilgrim's Pride Corp. vowed to crack down on chicken abuse after a video released by PETA showed workers stomping and kicking live chickens at a plant that supplies chicken to KFC.

PETA also wrung significant changes out of McDonald's in 2000 after a bruising publicity offensive concerning animal welfare.