The two Fortune 500 companies join Wal-Mart, Sony, Canon, FedEx, Intel, Toyota and other foreign manufacturers, some with long histories of hostility toward labor unions in other countries, to permit union workforces in China, China Daily reported Saturday.

"Fortune Global 500 firms have been our focus in the formation of trade unions among foreign-funded enterprises," Yang Honglin of the All-China Federation of Trade Unions said at a news conference.

Other federation officials said more than 50,000 workers at Wal-Mart's 108 locations in China have now signed collective contracts.

China Daily said the union contracts provide annual wage negotiations and other benefits. Some Western observers, however, say the state-controlled union group frequently sides with management in disputes and serves as a way for the Chinese Communist Party to keep control of its increasingly sophisticated working class, the International Herald Tribune reported.

Independent labor unions in China are rigorously persecuted, workers' rights groups say.