MADRID, May 21 (Reuters) - Spanish holding company Criteria plans to raise its stake in Telefonica to 10%, matching the government's recently acquired stake in the telecoms company, news website El Confidencial reported on Tuesday, citing unidentified sources.

Criteria, which is Caixabank's largest shareholder with a stake of more than 30%, already owns about 5% of Telefonica.

A 10% stake in Telefonica is worth about 2.38 billion euros ($2.58 billion) at the current market price.

The Spanish government concluded the purchase of its 10% stake on Monday to counterbalance the acquisition of a similar stake in Telefonica by Saudi Arabia's STC.

Criteria declined to comment on the report. ($1 = 0.9210 euros) (Reporting by Inti Landauro and Jesus Aguado Editing by David Goodman)