Mahindra & Mahindra fell the most in nearly three weeks on tax woes.
The stock fell as much as 3.6 per cent. It was the top loser on the S&P BSE Auto index.
In a regulatory filing the company said Q4FY16 margins could be impacted by around 100 bps.
It says the margin impact was due to expiry of excise duty exemption on products manufactured from its plant in Haridwar, its sole automotive plant in the north, from January 1.
Its shares have posted the biggest intra-day per cent fall since February 11.
Infrastructure cess proposed in Budget 2016-17 may impact volumes in the auto division, it said in the filing.
The company would pass on the tax hike to customers in due course, the filing said.