The European Commission said it would examine the 850-million Danish crown ($120 million) deal even though it is below the turnover threshold for EU scrutiny following requests from 13 European countries.

In recent years, the EU competition enforcer has taken a more aggressive policy toward mergers which do not meet its requirements for review, concerned that even small deals can harm competition without appropriate remedies.

"The transaction threatens to significantly affect competition in the market for cochlear implants and bone conduction solutions in the EEA (European Economic Area) and in the referring countries," the Commission said.

It said that it is best placed to examine the potential cross-border effects of the deal.

Cochlear will now have to seek EU approval before it can complete the deal.

The UK competition watchdog has given the companies until Dec. 13 to allay its concerns about the supply of bone conduction solutions in Britain, Cochlear said on Wednesday. The agency has no worries about the supply of cochlear implants.

Last week Cochlear said the Australian antitrust agency warned that the deal is likely to substantially lessen competition in the supply of non-surgical bone conduction devices in Australia, with a final decision set for March 16.

($1 = 7.0783 Danish crowns)

(Reporting by Foo Yun Chee; Editing by David Gregorio)

By Foo Yun Chee