"We have filed the petition today. It is expected to come to the court for further proceedings on Monday," said M Saravanakumar, president, Nokia India Thozhilar Sangam.
The workers' union is seeking a solution to the dispute between Nokia and the I-T department.
"It has been mentioned in the global deal that all Indian workers have to be transferred to Microsoft between January and March next year. The Nokia management should follow the procedures to implement that deal," Saravanakumar said.
The union, which claims to have the support of about 4,800 employees, had earlier said the parties concerned consider the issue involved the lives of 30,000. It has also said it wasn't satisfied with the way the company had handled the issue.
Responding to the union's move to join the case, a Nokia spokesperson had, on Friday, said, "We are happy the union is joining the case. We are all fighting for the same reason." On the union's criticism on the way the management had handled the issue, the spokesperson had said, "We are doing our best to solve the issue and protect the employees."