The U.K. Competition and Markets Authority said Wednesday that it has started a formal investigation into Microsoft Corp.'s planned acquisition of Nuance Communications Inc. to determine whether the merger would lessen competition within U.K. markets.
The regulator said it has set a deadline of March 9 for its phase one decision into the deal. It launched an initial review in December.
On Dec. 21 the European Union's antitrust authority unconditionally approved the deal, saying that it wouldn't significantly reduce competition and wouldn't raise any concerns.
The U.S. software giant said in April that it struck a deal to buy transcription-technology company Nuance, valued at $19.7 billion including Nuance's net debt, in a bet on the growing demand for digital tools within healthcare.