Spanish telecoms group Telefonica SA expects to raise its stake in China Netcom Group Corp to 10 percent in coming months, Chairman Cesar Alierta told Reuters on Monday.

Telefonica raised its stake in the Chinese telecoms operator to 7.2 percent from 5 percent last month. It had previously said it hoped to increase its stake to 10 percent by the end of last year.

We'll get to 10 percent. I think we'll do it in the next months, Alierta told Reuters on the sidelines of the Mobile World Conference in Barcelona.

Telefonica bought its 5 percent stake in China Netcom in 2005 for 418 million euros ($608.8 million) and paid another 309 million for the next 2.2 percent.

China Netcom is 70 percent owned by state-controlled China Network Communications Group, which has said it could sell some of its shares as long as it maintains majority control over the operator, the smaller of China's two fixed-line companies.

Telefonica shares were 0.5 percent lower at 0910 GMT, underperforming the DJ Stoxx index of European telecoms stocks which lost 0.3 percent.

Separately, Alierta declined to comment on a media report which said Telefonica planned to hold on to its 16.6 percent stake in Sogecable and not sign up to a takeover offer for the pay-TV group from its parent Prisa.

The stake is worth about 625 million euros at the 28 euros per share Prisa is offering in its buy-out bid.

A Telefonica source said the company would not announce its decision on Sogecable until the takeover offer ends at the end of April. (Reporting by Robert Hetz; Writing by Jane Barrett; Editing by David Holmes)