WASHINGTON (Reuters) - A tentative U.S. Senate deal has been reached to have President Barack Obama withdraw two of his embattled nominees to the National Labor Relations Board and offer a pair of new ones that organized labor helps pick, congressional sources said on Tuesday.

Under the possible agreement, Republicans would promise to clear the way to have the new nominees confirmed by August 1, the sources said. Republicans have opposed two of the pending nominees because their temporary appointments by the Democratic president were invalidated by a federal appeals court. The case is being appealed to the Supreme Court.

(Reporting By Thomas Ferraro and Richard Cowan)