Oracle has failed to produce enough evidence to convince the European Union (EU) that its plans to acquire Sun Microsystems are not anti-competitive, according to reports.

The database firm has offered $7.4bn (£4.5bn) for Sun, a purchase that would turn Oracle into a giant hardware and software company.

The EU is concerned that such a deal could put Oracle in a position to dominate the server market, particularly with MySQL, and has said that Oracle has done little to assuage these fears.

A spokesman for EU competition commissioner Neelie Kroes said that she had " expressed disappointment that Oracle had failed to produce, despite repeated requests, either hard evidence that there were no competition problems or, alternatively, proposals for a remedy to the competition problems identified by the European Commission", according to the BBC.

Oracle will be keen to avoid any further delays, and will have to work hard to change EU minds.

Sun announced this week that delays to the deal had led to a decision to cut 3,000 staff over the next 12 months.

The EU has until 19 January to make a final ruling on the merger.