Kyodo News reported that Japan’s Fair Trade Commission's request to BHP Billiton Ltd. for information regarding the mining giant's bid to acquire rival Rio Tinto Ltd has become legally binding.

The FTC made a formal request in September to BHP Billiton to provide information on the takeover bid amid concerns that the merger, if realized, could go against the principle of fair competition. The antimonopoly regulator has so far received no response from BHP Billiton and the request became legally binding Thursday, an FTC official said.

If BHP Billiton, the world's largest mining company, ignores the order, the FTC will examine the legality of the merger on its own and decide whether it breaches the country's antimonopoly law as early as the end of this month.

BHP Billiton could be slapped with a cease and desist order and face penalties if the FTC rules the tie up is illegal.

This is the first case for Japan to request information regarding a takeover bid between foreign entities based on the antitrust law, according to the FTC.

BHP Billiton now has until November 17th 2008 to respond on whether it will comply with the order.