LONDON, March 18 (Reuters) -
* The European Commission will on April 1 release preliminary 2018 carbon emissions data from energy-intensive companies in Europe covered by its Emissions Trading System (ETS), the Commission said on its website.
* The data is closely watched by the carbon market, and can affect EU ETS carbon prices.
* The number of carbon permits surrendered per installation for 2018 will be made available on May 2, it said. (Reporting by Susanna Twidale, editing by Louise Heavens)