UPDATE 1-Telefonica considers listing 10-15 pct of Latam unit

MADRID, Dec 3 (Reuters) - Spain's Telefonica SA is working on plans to list 10-15 percent of its Latin American unit, its chief executive said in an interview with the Financial Times published on Monday.

Cesar Alierta was quoted as saying the telecoms group could float the stake to "send the message that the sum-of-the-parts is much higher than the valuation of Telefonica".

A Latin American listing could be attractive to investors as the fast-growing region offers good prospects, especially compared with recession-struck Spain, where Telefonica's nine-month revenue tumbled 13 percent year-on-year.

Portuguese bank Espirito Santo values Telefonica's Latin American business at 39.4 billion euros ($51.2 billion), which means Telefonica could hope to raise more than 4 billion euros from floating a 10-15 percent stake, according to the paper.

The potential flotation is being worked on within the company, but has not been given board approval, it added.

Alierta said there were no further major asset sales or flotations being prepared and the group had "no intention to float our UK operations" in spite of recent analyst speculation.

Telefonica's chairman also said the company was on track to bring down net debt to near 50 billion euros from 58 billion after the listing of part of its German unit..

Debt-laden Telefonica has sold a number of assets this year, including part of its stake in China Unicom and call-centre business Atento.