Oracle has moved a step closer to its planned acquisition of Sun Microsystems after the European Union approved the takeover.

After it was given approval by the US Justice Department last summer, it is still requiring the backing of competition authorities in China and Russia, but Oracle has said it expected this to be forthcoming.

The Guardian has reported that in a memo to staff, Sun chief executive Jonathan Schwartz told his employees that they had to prepare for the change and praised Oracle's management.

He said: “With nine months of getting to know them, I've found Oracle to be truly remarkable, led by remarkable people. I've seen their commitment and focus, now they need yours.”

A statement from Oracle confirmed the EU approval for the acquisition, and said that it expects unconditional approval from China and Russia, and intends to close the transaction shortly.