FRANKFURT (REUTERS) - Volkswagen has admitted that 8 million vehicles were fitted with software capable of cheating diesel emissions tests in the European Union, a German newspaper said on Monday, citing a letter the carmaker sent to members of parliament.

The letter - dated Oct 2 and cosigned by the former government spokesman and current VW chief lobbyist Thomas Steg - says that vehicles with 1.2, 1.6 and 2.0 litre engines are affected, daily Handelsblatt reported in an advance copy of its Tuesday edition.

The authors of the letter apologise "for the wrongdoing of a few individuals" and promise to fully clarify the matters, the paper said.

A spokesman for VW said late on Monday that he did not know about the letter and could therefore not comment.

Volkswagen is under huge pressure to get to grips with the biggest business crisis in its 78-year history, which has wiped more than a third off its share price, forced out its long-time CEO and rocked both the auto industry and German establishment.

Up until now the carmaker has said it will have to refit up to 11 million diesel vehicles worldwide, including 2.8 million in Germany.

New Chief Executive Matthias Mueller will address workers at a staff gathering in Wolfsburg on Tuesday and is expected to brief the supervisory board on Wednesday, a source said.