NEW DELHI, April 1 (Reuters) - Coal India's (COAL.NS), opens new tab sales in March grew for the first time in six months, the company said on Wednesday, ​indicating a ramp-up in coal stocks ahead of peak summer amid ‌a shortfall in gas supply due to the U.S.-Israeli war against Iran.

Coal India's offtake, or sales to customers, rose 0.7% to 69.5 million tons in March, despite a 1.5% drop ​in its provisional output to 84.5 million tons, the company said in ​a stock exchange filing.

The state-run company accounts for over 80% ⁠of the country's production and is the world's largest coal miner by ​output.

Coal India's offtake fell for six consecutive months after a 7.6% jump in ​August, boosting inventory levels at power plants as temperate weather dented India's power demand in 2025.

The higher stocks have kept import demand subdued despite the peak summer season approaching, said ​Vasudev Pamnani, director at Gujarat-based coal trader iEnergy Natural Resources.

Domestic coal remained ​relatively more attractive in certain segments, he said, adding that disruptions in liquefied natural gas ‌supply ⁠and reduced gas-based power generation are expected to boost reliance on coal for power generation.

India, which relies on coal for nearly 75% of its power generation, is expected to lean more on the polluting fuel during the summer due ​to the gas ​shortage, Reuters reported in ⁠March.

Although gas accounts for only around 2% of India's total power generation, the South Asian country uses about 8-10 ​gigawatts (GW) of gas power during peak-demand periods or heatwaves.

In the ​absence of ⁠gas, India has asked its coal plants to run at maximum capacity and avoid planned outages, and has also asked industries to produce their own power ⁠through their ​captive generation plants to free up supplies for ​households.

India is set to experience a hotter-than-normal summer this year, with heat wave days in May expected ​to exceed the seasonal average.