Hitachi Ltd, NEC Corp and Casio Computer Co said Friday the launch of their merger on mobile handset operation will be delayed by about one month beyond it's original schedule in April. The three companies agreed in September to integrate their mobile phone operation in April this year by forming a new joint venture to boost their global competitiveness amid a saturated domestic market. But in joint statement issued Friday, Hitachi, NEC and Casio Computer said they put off the launch of their venture called NEC Casio Mobile Communications Ltd to lessen the impact on their businesses due to imminent delays in overseas antitrust screening procedures. NEC Casio Mobile Communications will be formed by merging NEC's mobile phone business with Casio Hitachi Mobile Communication Co, and existing venture firm founded by Casio and Hitachi in 2004.