India's largest carmaker Tata Motors reported a 56 percent slump in quarterly net profit on Tuesday due to weak earnings from its luxury British unit and sluggish domestic sales.

Consolidated net profit for the fourth quarter which ended March 31 slumped to 17.17 billion rupees ($268 million) from 39.18 billion rupees during the same period a year earlier, the Mumbai-based company said.

It came in below the expectations of 24 analysts surveyed by Bloomberg who had predicted a 40.6 billion-rupee profit for the auto giant, part of India's massive tea-to-steel conglomerate the Tata Group.

Tata Motors' consolidated net profit for the financial year also declined, falling to 139.86 billion rupees ($2.19 billion) from 139.91 billion rupees for 2013-14.

A 33 percent decline in profit at Jaguar Land Rover (JLR), which Tata Motors bought for $2.3 billion from Ford in 2008, contributed to the slide, the company said in a statement to the stock exchange.

The firm blamed the fall at JLR to "higher depreciation and amortisation", effectively higher write-offs, and "unfavourable revaluation of foreign currency debt and unrealised hedges".

Tata Motors remained upbeat about JLR's potential however, and said it was likely to invest nearly four billion pounds ($6.16 billion) in the luxury unit in coming months.

Earnings were also hit by a prolonged slump in sales of small commercial vehicles in India.

Losses at Tata's Indian operations continued to balloon and reached 11.64 billion rupees for the quarter and 47.39 billion rupees for the year.