French media and entertainment group Vivendi says cable company Altice is interested in buying part of its mobile subsidiary SFR in an operation that could be worth a reported 15 billion euros ($A23 billion).
But it said "no formal offer" was yet on the table and denied a report in the Les Echos financial newspaper that an agreement in principle had been reached.
Debt-laden Vivendi said last year it wanted to spin off SFR to focus more on media and content.
Its board in November approved a divestment plan under which new SFR shares could be issued on the stockmarket.
The head of SFR, Jean-Yves Charlier, told staff in an email on Monday that he wanted to put into perspective the "rumours" surrounding the interest shown by Altice, a French holding company that owns a leading internet cable provider, Numericable.
"Vivendi and SFR will study any opportunity that might result in a real strategic and industrial project," he wrote.
Les Echos put the 15 billion euro evaluation on SFR's purchase by Altice, and calculated that synergies would produce 6 billion euros in cost reduction.
It said Altice wanted to buy 50 per cent of SFR, and Vivendi would retain 32 per cent.
Observers saw such a deal as shaking up the order in France's mobile phone market, which currently counts four operators: Orange, SFR, Bouygues Telecom and Free Mobile.
The entry of Free Mobile into the market early 2012, with a cut-rate subscription strategy to grab market share, has driven down profits.
