HELSINKI (AP) — Nokia Corp. announced Monday that some 14 million mobile phone chargers could be dangerous for users and said it will replace them free of charge.

The chargers, bearing Nokia’s name and made by Chinese battery and auto part maker BYD Co., are models AC-3E and AC-3U, made between June 15 and Aug. 9 this year; and AC-4U, manufactured between April 13 and Oct. 25, 2009. They were mostly sold in Europe and North America.

Nokia said the chargers’ plastic covers might work loose and expose wiring, which could cause an electric shock if touched if the charger is plugged into a socket. It said it had received no reports of injuries or accidents related to the chargers.

Nokia is the world’s largest mobile phone maker with an estimated 38 percent global market share of all mobile devices. In the third quarter it sold 108.5 million units.

Based in Espoo near the Finnish capital, it sold 468 million handsets last year, up 7 percent on 2007.