Volkswagen revised its previous assumptions for global car market sales lower by 67 million vehicles for the period through 2018, Automobilwoche reported, citing a letter presented to VW's top management.

This means a loss for the global market during this period that is equivalent to an entire calendar year, said senior VW manager and former head of group sales Detlef Wittig in a letter presented to VW's executive board.

This effect would lead to sustainably lower group deliveries to customers versus the previous plan, and as a result to a lower financial result, he went on to explain.

Automotive News' German-language newspaper did not cite a specific reason for the revision, but many carmakers have had to retreat from previously ambitious retail sales targets following the economic crisis.

According to the report, Chief Executive Martin Winterkorn stuck to his target of surpassing Toyota <7203.T> as the world's largest carmaker by 2018.

Volkswagen could not be reached for a comment.

(Reporting by Christiaan Hetzner; Editing by Toby Chopra)