London, Feb. 9 (Reuters): Britain’s Vodafone Plc, the world’s biggest mobile phone company, indicated on Monday that it was weighing a possible bid for AT&T Wireless, the third-biggest US wireless firm, which is up for auction.

“Vodafone Group Plc announces that it continues to monitor developments in the US market and is exploring whether a potential transaction with AT&T Wireless is in the interests of its shareholders,” Vodafone said in a brief statement.

There has been speculation for weeks that Vodafone may join the $30-billion auction for AT&T Wireless.

AT&T Wireless, which is 16-per cent owned by Japan’s NTT DoCoMo, has already received an informal, all-cash take-over offer from Cingular, the number two wireless group controlled by SBC Communications Inc and BellSouth Corp, a source close to the talks said last month.