The European Commission just confirmed earlier reports it will begin an in-depth inquiry in to Nokia’s (NYSE: NOK) proposed $8.1 billion acquisition of GPS mapping provider Navteq. It was always likely after the EC began a detailed and ongoing investigation in to TomTom’s similar acquisition of the other map maker, TeleAtlas, in November.

Today’s new probe does not necessarily indicate Nokia’s purchase will be blocked, but the EC’s concerns are clear as to this simultaneous concentration in the market: “The US company Navteq is one of only two producers of navigable digital maps which offer complete coverage of Europe and North America. (The acquisition) might, in the light of the duopoly market for navigable digital maps and Nokia’s strong position on the market for mobile handsets, lead to a significant impediment of competition.”

Nokia notified the commission of its plan on February 19 after the pair announced the $8.1 billion buy-up in October. From Nokia’s original submission: ”The acquisition of Navteq is part of Nokia’s internet services strategy.”

Also today, the same EC department confirmed it had written to the Romanian government, questioning whether it had given Nokia state subsidies to open a handset-making plant in the country. State subsidies are governed by complex EC antitrust rules to guarantee fairness but the EC said the letter was “purely precautionary” (via Reuters).