Several labour unions including the All India Trade Union Congress and Centre of Indian Trade Unions had opposed the bill and were planning a one-day strike affecting workers from tens of factories next month.

The Tamil Nadu government passed the bill last week but it has yet to become law. At the time, it said those working 12 hours for four straight days would get three paid days off each week. But several workers raised concerns over proper implementation of the rule at factories.

"The government passed the bill aiming to attract big investments and increase employment opportunities for youngsters," said a statement from M.K. Stalin, the state's chief minister, on Monday.

A group of ministers at a Monday meeting told union representatives the state would not compromise on workers' welfare and that the extended working hours would apply only to certain types of factories approved by the government, the statement said.

The move was expected to boost industrial production in the state, which has attracted billions of dollars in investments from companies hoping to diversify their supply chain away from China, including Apple suppliers Foxconn and Pegatron as well as Nike shoemaker Pou Chen.

"The state government has only put the bill on hold, but it needs to withdraw the bill as there is a chance it looks to bring it back. We are going to hold our ground," said K. Bharathi, an activist with the Left Trade Union Centre.

(Reporting by Praveen Paramasivam in Chennai and Munsif Vengattil; Editing by Devika Syamnath and Deepa Babington)