The loss of Nano sales in its home market of India drags down earnings for the group, which also owns Jaguar Land Rover.
Group profit at Tata could be down by as much as 57 per cent, a record for the company and the largest decline since former chairman Ratan Tata acquired JLR in 2008 from Ford.
Bloomberg reports that JLR accounted for as much as 72 per cent of Tata’s revenue in the last three months of 2012.
One analyst told Bloomberg: “Tata is no longer an aspirational brand and in India, cars are an aspirational purchase.
“They [Tata] seem to be trying to do something about this but those models are some time away, so the big challenge is how do you hold on while the new models come in.”
Tata has tried running several promotions in its home market to drive sales, including offering to buy back Manza saloons and allowing customers to purchase a new Nano using their credit cards.
So far, however, the deals have failed to bring back buyers.
Market-watchers suggest that Tata will need to introduce new passenger car models tailored to the Indian market to turn the situation around.