LONDON (Reuters) - Sales of electric and plug-in hybrid cars in the European Union almost trebled to over 1 million vehicles last year, accounting for more than 10% of overall sales, data showed on Thursday. The jump in sales shows electrified vehicles are becoming more mainstream products after years of being a niche market and it came at a time when overall EU car sales plunged nearly 24% to 9.9 million because of COVID-19 lockdowns. The data released by the European Automobile Manufacturers Association (ACEA) showed sales of fully-electric and plug-in hybrids surged to 1.046 million vehicles from 387,808 in 2019. Sales of self-charging hybrid cars climbed 59% to 1.182 million last year while petrol and diesel vehicle sales fell 37% and 32% respectively, the data showed. Petrol cars remained the biggest seller, however, accounting for 48% of all EU sales. As well as having to meet stringent new EU carbon emissions targets, carmakers benefited from government subsidies for electric vehicles as part of pandemic recovery programmes, especially in France and Germany. Sales of fully-electric vehicles more than doubled to 538,772 from 247,854 a year earlier.