The logo of German carmaker Volkswagen is seen on a Volkswagen Golf car at a showroom of Swiss car importer AMAG in Duebendorf, Switzerland February 12, 2016. REUTERS/Arnd Wiegmann

FRANKFURT (Reuters) - Top managers at Volkswagen VOWG_p.DE do not expect an agreement before the end of March with U.S. authorities over the German carmaker's rigging of emissions tests, German monthly Manager Magazin reported on Friday, citing company sources.

Negotiations are dragging on because the U.S. Environmental Protection Agency is demanding a long distance test of a technical solution proposed by Volkswagen, the magazine said.

It also said the costs for recalls, buybacks of affected vehicles and compensation of customers would be significantly higher than previously expected.

Volkswagen was not immediately available for comment.