US regulators have forced AT&T to ask shareholders whether they want a non-binding vote on executive pay in a move that will bolster investors' efforts to have a greater say on the compensation of America's corporate leaders.

The decision by the Securities and Exchange Commission, contained in a letter seen by the Financial Times, is a major blow to AT&T, which has been one of corporate America's staunchest opponents of an unprecedented campaign by investors and lawmakers to introduce a UK-style, yearly vote on executives' pay.