BT is in preliminary talks to buy mobile operator O2 from spanish telecoms giant Telefonica.
"All discussions are at a highly preliminary stage and there can be no certainty that any transaction will occur," BT said.
The potential deal sent markets and commentators into a frenzy of speculation that parent companies of UK mobile operators are seriously looking to exit the market.
The moves are being seen as very positive for BT which will not overpay for market share.
One investment bank valued O2 at $9bn while another put the price tag at $9.6bn.
In a statement to the Spanish stock market, Telefonica, said: "Telefonica informs that, although it is in talks with British Telecom, these talks are in a highly preliminary phase and there is no certainty that a transaction will take place,"