The decision comes a week after Ratan Tata unveiled the world's cheapest car 'Nano' to be manufactured in Singur.

Dismissing all 11 petitions challenging the process of acquisition of 997.11 acres of land at Singur, a division bench comprising Chief Justice S S Nijjar and Justice P C Ghosh observed that there had been "no colourable excercise of power" by the West Bengal government in acquiring the land.

On February 9 last year, petitioner Joydeep Mukherjee had moved a writ petition challenging the acquisition of 997.11 acres at Singur in Hooghly district, about 40 km from the metropolis.

Mukherjee along with 10 other individuals and associations, who joined the case as added petitioners, claimed that the land had been acquired without following the provisions of the Land Acquisition Act, 1894 and the Land Acquisition (Companies) Rules, 1963.

The petitioners had claimed that agricultural land was acquired and accordingly it was illegal.

However, the state claimed before the court that it had gone by the rulebook in acquiring land at Singur for the Tata motors plant as also for ancillary industries.

Hearing was held in the matter on several occasions and the court had entertained all the parties in the case.

The world's cheapest car, which has already set the market ablaze, is to be manufactured at the Singur factory where construction of the mother plant is on a war footing to meet the commercial rollout deadline of mid-2008.