Bajaj Auto Ltd has won another battle against two-wheeler rival TVS Motor Co Ltd, as it has been granted the patent for its 'ExhausTEC' technology by the Controller General of Patents, Designs and Trade Marks. The decision could spell trouble for TVS, which has allegedly been using the same technology on its popular Apache series.

''The patent arms us with power of infringement,'' said Bajaj Auto vice-president S Ravikumar. ''Only time will tell what we do next.''

This is the second victory for Bajaj over TVS on property rights. The earlier clash occurred when TVS Motors unveiled its 125cc bike Flame in August 2007. Bajaj Auto promptly filed a case alleging that TVS had used the digital twin spark technology (DTSi) patented by it in 2002.

After an injunction by the Madras high court February 2008 in favour of Bajaj Auto, TVS Motors had to withdraw and re-launch the motorcycle with single-spark technology. The injunction also barred TVS from using twin-spark technology on any of its subsequent products.

Ina a media statement Ravikumar said Bajaj Auto had been granted the patent last month by the Indian patent office. This was published in the Patent Gazette of 27 March.

''ExhausTEC significantly improves low / mid-range torque in a single cylinder four-stroke engine, employing a chamber of pre-determined volume attached to the exhaust pipe,'' the statement says, adding that Bajaj has used it on its motorcycles since August 2004, when it filed a patent for this technology.

When TVS unveiled its new series in 2007, Bajaj said it ''observed a chamber attachment looking similar to its ExhausTEC on a product displayed'' at the launch. In December, Bajaj served a notice to TVS regarding this ''potential infringement.''

A couple of weeks later, TVS filed a 'pre-grant opposition' before the patent office under Section 25(1) of the Patents Act, 1970, opposing the grant of patent for this invention. In January, it replied to the Bajaj notice informing it about the filing of the opposition, whilst denying that this invention of Bajaj had been incorporated in their product, the release said.

A pre-grant opposition challenges a patent application by citing documents available in the public domain which are called 'prior art', to prove that the technology already exists.

The patent office dismissed TVS' opposition on 5 March this year and granted a patent to Bajaj for 20 years from the ''priority date of 6 August 2004''.

''I am clueless, I have asked our legal counsel to look into the matter,'' said Cecil K Dewars, vice-president, corporate communications, TVS Motor Co.

Legal experts say the ruling is not final, and TVS could still challenge the decision through a post-grant opposition. However, the current ruling will weigh against TVS unless it can show more 'prior art'.

Alternatively, it could continue to sell its bike, questioning the very validity of the patent, and face Bajaj in court should it file a legal suit.