UK telecoms group BT could take a step forward in its bid to buy a mobile phone operator on Monday, according to a report.BT may announce exclusive talks with either EE or Telefonica's O2, news agency Bloomberg cited unidentified sources as saying.BT is believed to favour O2, but has continued to talk to EE's owners Orange and Deutsche Telekom to try to extract a better price and structure, Bloomberg said.The British former state-owned telecoms operator is trying to get back into the lucrative mobile phone market after hiving off its former MMO2 mobile business, previously known as BT Cellnet, in 2001.It comes amid speculation about wider consolidation in the industry as mobile operators such as Vodafone try to expand their presence in fixed line and broadband operations, which has led to talk about tie-ups with rivals such as Sky.