LONDON, March 17 (Reuters) - "Mega-heatwaves" like the one that hit Russia and other parts of eastern Europe last year are up to 10 times more likely to occur over the next 40 years and could have serious consequences, scientists said on Thursday.

In a study published in the journal Science, researchers from Portugal, Switzerland, Germany and Spain said the 2010 heatwave was hotter and more widespread than Europe's 2003 heatwave, but another one like it was unlikely until after 2050.