Centrica to buy 20 percent of British Energy-media

LONDON, May 10 (Reuters) - Centrica Plc (CNA.L) will pay French group EDF (EDF.PA) the equivalent of 2.3 billion pounds ($3.4 billion) for a 20 percent stake in British Energy instead of 3.05 billion for 25 percent, according to media reports.

No one at Centrica could be reached for comment immediately.

After a sharp drop in electricity prices hit British Energy's expected revenue, Centrica shareholders had urged the company not to overpay for the nuclear power generator and insisted it renegotiate the deal's terms, the Times reported in its Monday edition.

The Daily Telegraph's website also said EDF had reached a cut-price deal with Centrica, while the Financial Times said the deal would value British Energy at around 10 percent less than the 12.4 billion pounds ($18.2 billion) it paid last year.

Barring last-minute hitches, an agreement should be announced on Monday, the FT said, citing unnamed people close to the deal.

Centrica and EDF agreed to the deal in principle last summer, but have been at an impasse since because electricity prices, the main influence on British Energy's value, have halved.

Key to a deal was a side agreement under which EDF would buy Centrica's 51 percent stake in Belgian utility SPE. (Reporting by David Holmes, editing by Leslie Gevirtz)