Electricite de France SA's (EDF.FR) chairman and chief executive Henri Proglio Thursday warned that the group could drop all plans to build new nuclear reactors in the U.K. if returns on its investments aren't guaranteed.

"We would have legitimacy [to build new nuclear reactors in the
U.K. ] given our position in this country," where EDF already operates 15 reactors, Mr. Proglio said at a press conference. "But we won't go without a formal guarantee of returns on our investments," he added.

EDF and the
U.K. government are currently in talks over the planned project to build as many as four new nuclear reactors there and the discussions are currently focusing on the minimal price that British customers would pay for power from the reactors and which would ensure acceptable returns for EDF.

The plans, first mentioned in 2006, have faced many hurdles and delays and a negative outcome of the current negotiations could further call into question the commercial viability of such a project, at least in
Europe .

The talks are conducted "with much intensity," Mr. Proglio said, adding he still expected the negotiations to be finalized by the end of the first quarter this year.

Only once the returns guaranteed would EDF finalize discussions to bring in new partners into the project, after Centrica PLC (CNA.LN) dropped out of it earlier this year.