US fund manager Tweedy Browne may scrap or scale back investments in Germany because it is concerned about corporate governance at Volkswagen.

The Financial Times said the fund manager, which has US$13bn under management and has pushed through change at several companies, is talking to other Volkswagen shareholders to force out Ferdinand Piech, the head of the car maker's supervisory board.

Piech is one of the controlling shareholders of luxury carmaker Porsche - Volkswagen's largest shareholder, according to the report.

He sided with the unionised employee representatives on Volkswagen's board in agreeing to their choice of Horst Neumann as new head of personnel, against the will of his CEO and Volkswagen brand group chief, Wolfgang Bernhard, sources familiar with the supervisory board proceedings told Reuters last month.

The fund manager has about US$700m invested in nine German companies and is one of Volkswagen's six top shareholders with a stake of around 1%, the FT said.

It wants Piech to step aside and is also planning to vote against Porsche executives on Volkswagen's supervisory board, the report added.