TOKYO (Bloomberg) - NEC Corp., Casio Computer Co. and Hitachi Ltd. will merge their mobile-phone handset operations in April. NEC will start with a 66 percent stake in the venture, which will rise to 70.74 percent by June.

Casio will have 20 percent and Hitachi will have 9.26 percent.

Hitachi the announcement in a joint statement to the Tokyo Stock Exchange on Monday.