Nokia has received regulatory approval from China for the sale of the bulk of its Devices & Services unit to Microsoft – a key milestone as it seeks to finally close the €5.4 billion deal.

The Finnish vendor said last month that the sale would close in April rather than during the first quarter as originally anticipated, because it was awaiting approval from a number of unnamed antitrust authorities in Asia.

Chinese approval, which comes from the country’s ministry of commerce, was a key hurdle along with that from the European Commission and the US Department of Justice.

Nokia and Microsoft also reaffirmed they now expect the transaction to close this month.

The Finnish vendor also pointed out that the approval process has involved a thorough review of its patent licensing practices by competition authorities around the world.

“During that process, no authority has challenged Nokia’s compliance with its FRAND undertakings related to standard-essential patents (licensing on fair, reasonable and non-discriminatory terms) or requested that Nokia make changes to its licensing program or royalty terms”.

However the company does faces a court filing in India from the Tamil Nadu tax department, which  alleges it has unpaid taxes of approximately €300 million ($414 million). This is separate from an earlier tax claim made against Nokia in India.

Nokia strongly contests the claim and has said in the past that tax proceedings in India will not slow up progress of the Microsoft deal.