An employee stands inside the newly inaugurated plant for the Tata Nano car at Sanand in the western Indian state of Gujarat June 2, 2010. India's largest vehicle maker, Tata Motors, said on Tuesday its sales in May rose 41 percent from a year earlier to 56,779 units. REUTERS/Amit Dave (INDIA - Tags: TRANSPORT BUSINESS)

Tata has offered to replace the starter motor on all old Nano models, but said the move was not related to safety concerns surrounding the world's cheapest car.

The five-seater hatchback, which has suffered a series of fires since its launch in 2009, costs as little as 140 880 rupees (R22 500) for the no-frills model.

A Tata spokesman said the company was offering the replacement starter motors for cars produced between July 2009 and October 2011 because “we have a new one and it further improves the car's performance”.

“There are no safety worries,” he said.

Tata introduced an updated version of the egg-shaped Nano in November to boost customer appeal with a wider range of colours and more luxurious interiors along with better fuel efficiency and engine power.

The Nano's sales have largely disappointed amid concerns over the engine fires, production delays, and cut-throat competition in the small-car segment of India's vast vehicle market.

The carmaker has blamed the fires on “isolated” and “unrelated” reasons.

The Tata spokesman would not disclose the cost of the upgrade, but the Finance Chronicle newspaper said the company - one of India's biggest business conglomerates - would spend up to 1.1 billion rupees (R175 million) replacing the starter motors of 145 000 Nanos.

Last November, Tata offered Nano owners the option of installing additional safety equipment, but said the move did not amount to a recall.

Observers say the company has failed to get its marketing right, simply selling the Nano as “cheap” rather than an aspirational product for India's emerging and status-conscious middle classes. - Sapa-AFP