U.S. software company Oracle will present to European Union regulators on Dec. 10 its case for buying computer maker Sun Microsystems, two people with knowledge of the matter said on Wednesday.

The European Commission has objected to the $7 billion deal, saying the combination of Sun's MySQL database product and Oracle's products could dent competition in the database market, a Sun regulatory filing earlier this month showed.

The EU competition watchdog last week extended a deadline for reviewing Oracle's plan to Jan. 27 from Jan. 19 after the world No. 3 software maker sought more time to tackle concerns the deal may be anti-competitive.

Oracle has asked for a hearing which has been fixed for Dec. 10, one of the persons told Reuters.

Competitors can usually attend the closed hearings to argue their case.

The U.S. Department of Justice approved the deal in August.

Sun is the developer of Java software, among the world's most widely used computer languages. Its MySQL database is used to run popular websites operated by companies include Google Inc, Facebook and Amazon.com.

Its main customer base is small and mid-sized businesses. Its primary competitor is Microsoft Corp's SQL Server.

(Reporting by Foo Yun Chee)