India's Tata Motors Q1 net profit halves on forex loss post-Brexit vote

* Tata Motors Q1 net profit down 57 pct post-Brexit

* JLR Q1 operating margin at 12.3 pct vs 16.4 pct a year ago

* Tata Motors CFO says monitoring, assessing UK, EU markets (Adds executive comments, result details)

By Promit Mukherjee and Aditi Shah

MUMBAI/NEW DELHI, Aug 26 (Reuters) - Foreign exchange losses after Britain's decision to leave the European Union and higher expenses offset strong sales growth at India's Tata Motors (BSE: TATAMOTORS4.BO - news) , more than halving its net profit in the April-June quarter.

Tata Motors' profit was hit by forex losses of 22.96 billion rupees ($342.43 million) mainly due to pound depreciation post-Brexit vote and adverse commodity derivatives impact of 1.67 billion rupees in the quarter, it said in a statement on Friday.

Chief Financial Officer C Ramakrishnan said while the company cannot predict whether the foreign exchange impact will continue, it will be cautious and closely monitor and assess market conditions in Britain and the EU.

"We need to be careful ... that is why we have a fairly robust hedge book so we are not subject to so much volatility," Ramakrishnan said, adding that major events that suddenly trigger significant currency movements tend to be a surprise.

The majority of the forex loss was at its British luxury unit Jaguar Land Rover where profit after tax fell to 304 million pounds from 492 million pounds in the year ago quarter, despite a 9 percent increase in revenue thanks to strong sales of its Jaguar XE compact saloon and Discovery Sport SUV.

"The operating performance in the quarter reflects the overall higher wholesales, offset by adverse foreign exchange impact of 207 million pounds including revaluation of 84 million pounds, mainly euro payables resulting from depreciation in the pound following the Brexit vote," Tata said in a statement.

As a result, operating margins at JLR fell to 12.3 percent during the quarter from 16.4 percent in the year ago quarter.

Margins were also impacted by lower local market incentives earned in China this quarter compared with a year ago and a change in the product portfolio to include more high-volume-low-margin vehicles like the Jaguar XE.

Tata Motors, India's top automaker by revenue, said consolidated net profit for the quarter fell to 22.36 billion rupees compared with 52.31 billion rupees in the year-ago quarter. Analysts on average expected a profit of 24.2 billion rupees, according to Thomson Reuters (Dusseldorf: TOC.DU - news) data.

Total (LSE: 524773.L - news) income from operations rose 9 percent to 670.56 billion rupees.

Profit was helped by a one-time gain of 4.78 billion rupees in an insurance payment for damage caused to JLR cars in an explosion at Tianjin port (Shanghai: 600717.SS - news) in China last year.

Shares (Berlin: DI6.BE - news) in Tata Motors, valued at $23.7 billion, ended the day 2 percent higher after rising as much as 4 percent in a weak Mumbai market. ($1 = 67.0500 Indian rupees) (Writing by Aditi Shah; Editing by Sunil Nair and David Evans)