BERLIN, June 27 (Reuters) - Mercedes-Benz is investing more than previously planned in combustion engine technology, including 14 billion euros ($15 billion) this year on its passenger cars, its chief executive told German publication Wirtschaftswoche.

The premium carmaker was investing in factories and in research and development, reworking the drive train of its electrified combustion engine cars so that it "lasts well into the next decade", Ola Kaellenius said in comments published on Thursday.

"Our engines will always be at the very highest technological level. Otherwise, we would suddenly stall our combustion engine business in 2027/28," he added.

($1 = 0.9355 euros) (Reporting by Victoria Waldersee and Miranda Murray, editing by Thomas Seythal)