Japan's Toyota said production at its two Indian plants has fallen by half as many of its unionised workers remain off the job over a pay dispute.
The Toyota workers and the company's management at two plants near the southern high-tech city of Bangalore have been negotiating the pay issues for 10 months.
"Production has declined 50% to 350 cars from 700 cars a day," senior Toyota Kirloskar Motors executive Shekar Viswanathan told a news conference in Bangalore late on Friday.
Toyota Kirloskar Motor Private Ltd is the Indian unit of the world's biggest carmaker.
Its Bangalore complex produces some 310,000 autos annually, including Toyota's flagship Camry sedan, the Corolla, and the Prius hybrid, mostly for the Indian market.
Just 300 of the 4,200 unionised employees have resumed work, with others staging protests outside the plants almost a fortnight since the company lifted an eight-day lockout, Toyota said.
The carmaker had said workers could return to work on March 24 provided they signed a good conduct pledge after it suspended some workers over accusations they had disrupted production and made threats to supervisors.
Viswanathan dismissed the unions claims that the management's "good conduct" pledge had clauses preventing the workers from union activity.
Toyota's plant problems come in the wake of other, sometimes violent, labour disturbances at Indian car factories in recent years.
In 2012, workers at India's top carmaker by sales, Japan's Suzuki Motor's unit Maruti Suzuki India, went on a rampage, killing one executive and injuring over 100 others in a row over pay and working conditions.