Top cellphone maker Nokia said on Monday it would replace 14 million chargers made by China's BYD Co Ltd, saying the chargers could fall apart.

"We are undertaking this exchange programme as a proactive, precautionary measure. We are not aware of any incidents or injuries relating to these three (models of) chargers," said Nokia spokesman Doug Dawson.

Nokia said BYD would cover all costs from replacement. An average charger sales price to phone manufacturers is around $1.

"The plastic covers of the affected chargers could come loose and separate, exposing the charger's internal components and potentially posing an electrical shock hazard if certain internal components are touched while the charger is plugged into a live socket," the Finnish firm said.

BYD was not immediately available for comment.