The European Commission has issued its formal "statement of objections" over Oracle's planned acquisition of Sun Microsystems, Sun said in a regulatory filing Monday.

The move is a procedural step in which the Commission lays out its preliminary views about how it thinks the merger might infringe Europe's competition laws. The filing of the statement was rumored last week to be imminent, and follows the Commission's decision in September to launch an in-depth investigation of Oracle's acquisition of Sun.

"The Statement of Objections sets out the Commission's preliminary assessment regarding, and is limited to, the combination of Sun's open source MySQL database product with Oracle's enterprise database products and its potential negative effects on competition in the market for database products," Sun said in its 8-K filing with the U.S. Securities and Exchange Commission.

Oracle and Sun can now respond to the document by presenting arguments in response to the Commission's concerns.

The statement of objections, which was issued on Monday, is "a preparatory document that does not prejudge the European Commission's final decision," Sun said in the filing. It noted that any final decision can be appealed to the European Court of First Instance.