Leyland plans Rs 250 cr unitsS KALYANA RAMANATHAN / New Delhi March 20, 2006Ashok Leyland is setting up two manufacturing units at a cost of Rs 250 crore. One will make engines for heavy commercial vehicles and the other, gear boxes.It is also introducing a voluntary retirement scheme to cut down the work force at its mother plant at Ennore in Tamil Nadu from 5,000 to 4,250.According to a wage settlement agreement arrived at on January 31 this year, the effective work time every day per worker per shift at Ennore will move up to 430 minutes from 350 minutes. Company sources said the wage settlement was based on an