FTSE edges lower on weaker energy shares, doubts over Greek talks

* Blue-chip FTSE 100 index down 0.2 percent

* Greece uncertainty prompts investors to be cautious

* Broker downgrades hit Centrica (LSE: CNA.L - news) , Fresnillo (Other OTC: FNLPF - news) shares

By Atul Prakash

LONDON, Feb 16 (Reuters) - Britain's top share index retreated from a five-month high on Monday, with some companies slipping on broker downgrades while energy shares tracked a fall in oil prices.

Doubts over the outcome of euro zone talks on Greece's debt also made investors cautious, analysts said.

The UK Oil and Gas index was down 0.8 percent, while oil prices fell 1.3 percent.

Online gambling firm 888 Holdings dropped 14 percent after the company said talks on a takeover by William Hill (Other OTC: WIMHY - news) had ended due to a breakdown over the price with a key stakeholder. William Hill was up 0.8 percent.

Downgrades from top brokers hit some firms, with Centrica down 2.8 percent after Citi cut its price target to 285 pence from 310 pence. It also came under pressure following media reports speculating about its results, traders said.

Fresnillo was down 3.7 percent after Morgan Stanley (Xetra: 885836 - news) reduced its stance to "equal weight" from "overweight", while Intertek Group (Other OTC: IKTSF - news) was down 3.6 percent after Jefferies downgraded the stock to "hold" from "buy".

The blue-chip FTSE 100 index was down 0.2 percent at 6,861.02 points by 0857 GMT, retreating from a five-month high in the previous session, with Greek concerns hurting sentiment.

"Scepticism and fear still abound about a debt agreement and Greek exit from the single currency, with what would appear still significant distance to cover before a compromise," Mike van Dulken, head of research at Accendo Markets, said.

Greece said on Sunday it was confident of reaching agreement in negotiations with its euro zone partners but reiterated it would not accept harsh austerity strings in any debt pact.

Germany's Finance Minister Wolfgang Schaeuble said, however, that he was not very optimistic that Greece and its peers would reach a deal on Monday. The talks are due to begin at 1400 GMT in Brussels.

Greece's share index fell 3.4 percent, while the country's main banking index was down 6.4 percent.

On the positive side, brewer SABMiller (LSE: SAB.L - news) rose 2 percent, the top gainer in the FTSE 100 index, with traders pointing to mergers and acquisitions talks as the main driver for the rally.

3G Capital (Other OTC: CGHC - news) , an investment firm run by a group of Brazilians, has been weighing up a 75 billion pound ($115 billion) takeover bid for SABMiller, the Mail on Sunday said, citing sources. ($1 = 0.6491 pounds) (Editing by Hugh Lawson)