The Indian penalty follows heightened regulatory scrutiny of the auto industry in China, the world's largest auto market. Several global car and spare parts makers have been fined, or are being investigated, by China's anti-monopoly regulator, the National Development and Reform Commission.

The Competition Commission of India (CCI) said in a statement it had fined the 14 automakers after its investigation showed they were restricting access to spare parts, which in turn made them more expensive for consumers.

It listed the automakers fined as the local unit of Honda Motor Co (>> Honda Motor Co Ltd), Toyota Motor Co (>> Toyota Motor Corp), Volkswagen AG (>> Volkswagen AG) and its unit Skoda Auto, BMW AG (>> Bayerische Motoren Werke AG), Daimler AG's Mercedes-Benz (>> Daimler AG), Fiat SpA (>> Fiat SpA), Ford Motor Co (>> Ford Motor Company), General Motors Co (>> General Motors Company) and Nissan Motor Co (>> Nissan Motor Co Ltd).

Local carmaker Tata Motors Ltd (>> Tata Motors Limited) was handed the highest penalty of 13.46 billion rupees. The other Indian carmakers fined were Maruti Suzuki Ltd (>> Maruti Suzuki India Ltd), Hindustan Motors Ltd (>> Hindustan Motors Limited) and Mahindra & Mahindra Ltd (>> Mahindra & Mahindra Limited).

The fine, equivalent to two percent of the carmakers' three-year average India revenue, is payable within 60 days, the regulator said.

"The anti-competitive conduct... has restricted the expansion of spare parts and independent repairers segment of the economy to its full potential, at the cost of the consumers, service providers and dealers," it said in the statement.

In a statement, Ford's India unit said it was reviewing the order and its implications, adding that the company had been working to enhance the availability of parts.

A Tata Motors spokeswoman also said the company would study the CCI order before making any comment.

Mahindra & Mahindra said it planned to appeal the watchdog's order. A Honda executive in India was not available for a comment, while a Maruti spokesman declined to comment.

The India representatives of the other carmakers did not immediately respond to request for comment.

The CCI said it had launched its investigation in 2011 after receiving information that spare parts made by some companies in India were not freely available in the market, resulting in higher prices for the parts and repair and maintenance services.

It said it had asked the carmakers to rectify their anti-competitive behavior, which it said impacted 20 million customers.

(Editing by Sumeet Chatterjee and Miral Fahmy)

By Aditi Shah