It had sold 49,304 vehicles in May 2013.
Domestic passenger as well as commercial vehicle sales declined by 24 per cent to 34,334 units in May, down from 45,430 units a year earlier.
Sales of passenger vehicles in May 2014 stood at 9,230 units, down 17 per cent, from 11,134 vehicles sold in the same month of last year.
The company sold 6,932 units of Nano, Indica and Indigo cars and 2,298 units of Sumo, Safari, Aria and Venture vehicles in May, the company said in a statement.
In the commercial vehicles segment, domestic sales declined by 27 per cent to 25,104 units from 34,296 units in May last year.