MADRID, June 28 (Reuters) - Spanish holding company Criteria said on Friday it raised its stake in telecom giant Telefonica to 9.99%, almost matching the stake the Spanish government recently bought in the company.

Criteria bought 4.91% of Telefonica shares, the company said on Friday, and intends to buy a further 0.2% so that its stake will surpass the 10% held by the government, making it the telecom group's largest shareholder.

A 10% stake in Telefonica is worth about 2.25 billion euros ($2.41 billion) at the current market price.

The Spanish government last month concluded the acquisition of a 10% stake in Telefonica to counterbalance the acquisition of a similar stake built by Saudi Arabia's telecom firm STC in December.

Criteria is the biggest shareholder in lender Caixabank . It also holds significant stakes in Spanish gas firm Naturgy, construction group ACS and real estate company Colonial.

($1 = 0.9351 euros) (Reporting by Inti Landauro Editing by Tomasz Janowski)