KOLKATA: The political agitation at Singur near the Tata Motors project site cast its shadow on the operations of another automobile company, that of Hindustan Motors Ltd. The C. K. Birla group company on Wednesday put up a notice at its factory gate shutting down its production for a day. An official spokesperson of the C. K. Birla group (which controls HM) said that the factory had advanced its weekly off from Saturday to Wednesday in view of the congestion on the Durgapur Expressway. The sprawling HM factory, built nearly 70 years ago and billed as the largest of its kind, is uptil now the State's lone auto unit. To a question on whether production was getting affected by the virtual road blocade there, the HM official said that while the factory was not carrying huge stocks but some materials were already on hand. HM, which sells 15,000 Ambassador cars annually, makes 750 of these cars at the unit at Uttarpara which is located some 20 km from the Tata Motors project site. "There has been no production curtailment due to the agitation uptil now,' the official said adding that in case the agitation continued, ways and means would have to be found to tackle the situation.