JLR's China retail sales nearly halved in the quarter as demand for cars from the Asian economic powerhouse shrank for the first time since the 1990s. The write-off has been attributed to slowing sales in China, technology disruptions linked to a shift towards eco-friendly hybrid and electric vehicles, and also the rising cost of debt.
The remaining half is understood to come from a lowering in the value of past investments in product development and engineering - recognition from Jaguar Land Rover that it is unlikely to reclaim previous investments with future sales.
Tata Motors Ltd shares had their biggest drop in 26 years after the company posted a record loss in Indian corporate history because of a writedown in its luxury Jaguar Land Rover Automotive Plc unit.
The firm said "significant market, technological and regulatory headwinds" were affecting the sector, while investment in new models and changing technology was still high.
The Tata Group firm reported a 8 per cent decline in domestic sales to 54,915 units in January as compared with 59,441 units in the same month past year.
"Weak sales in China and de-stocking impacted JLR", Tata Motors said in a release.
Retails in United Kingdom were up 18 percent as against an industry-wide drop of 3.8 percent.
Commenting on the step, JLR Chief Executive Ralf Speth said, "We are announcing a non-cash exceptional charge to reduce the book value of our capitalised investments".
While the December quarter performance of JLR was muted and the company will continue to be in the red for 2018-19, it expects to turn profitable and free cash flow positive in the fourth quarter, on back of all the cost saving and restructuring measures under way at JLR.
As part of the plans, JLR last month announced investments worth hundreds of millions of pounds to produce electric drive units at Wolverhampton. This is expected to result in a one-time exceptional redundancy cost of around £200m.
However, JLR is also planning a programme to accelerate the business, which is focused on longer-term investment as legacy carmakers across the world transition from fossil fuel-powered vehicles to battery technology.
JLR's revenue, however, declined 1 per cent to 6.2 billion pounds.
Tata Group Chairman N Chandrasekaran said the company's domestic business continues the strong momentum and has delivered market share gains as well as profitable growth.