April 25 (Reuters) - The Sri Lankan stock market was shut half an hour into trading on Monday, after shares tumbled nearly 10% in their first session since the central bank doubled its interest rates two weeks ago to tame inflation amid a devastating economic crisis.

* The CSE All-Share index closed 7.6% lower at 7,513.85 after falling as much as 9.6%. It has plunged nearly 40% this year.

* "Please note that the Market has been halted and shall be closed for the rest of the day due to the S&P SL20 index dropping over 10% from the previous close," CSE said on its website https://www.cse.lk.

* The S&P SL20 closed 12.6% lower.

* The Central Bank of Sri Lanka on April 8 raised its key interest rates by an unprecedented 700 basis points to rein in inflation that has soared due to crippling shortages of basic goods in the heavily indebted country that has little money left to pay for imports.

* Sri Lanka's central bank said earlier this month that it had become "challenging and impossible" to repay external debt, as it tries to use its dwindling foreign exchange reserves to import essentials such as fuel.

* S&P Global Ratings has lowered Sri Lanka's foreign currency rating to 'CC' from 'CCC', while Moody's has downgraded Sri Lanka's rating to 'Ca' from 'Caa2', citing the crisis.

* Protests have raged over the government's handling of the economy.

* The International Monetary Fund said on Saturday it held "fruitful technical discussions" with Sri Lanka on its loan request, while the World Bank said it was preparing an emergency aid package for the country.

* John Keells Holdings, LOLC Holdings and Expolanka Holdings, among Sri Lanka's largest companies by market value, plunged 16%-20% to weigh down the CSE All-Share index.

* For a report on global markets, click (Reporting by Chris Thomas in Bengaluru; Editing by Vinay Dwivedi)