Suzuki Motor chairman Osamu Suzuki has said it was unclear when an international arbitration court will rule on its 2-1/2 year dispute with Volkswagen over their failed partnership.

Reuters noted that Suzuki filed for international arbitration in November 2011, after Volkswagen refused to sell back a 19.9% stake in Suzuki it acquired in January 2010 for EUR1.7bn (US$2.3bn).

Earlier this month, sources familiar with the matter told Reuters that a London-based arbitration court had wrapped up witness hearings and was expected to issue a ruling before the end of the year.

"It's unclear," the 84-year-old chief executive told the news agency in Tokyo when asked about the likely timing of a ruling. Pressed on whether the two companies could reach a settlement, he said repeatedly: "We are the ones that took this to court."

The two automakers agreed on a tie-up in December 2009, saying they'd work together on technologies in areas such as hybrid and electric vehicles, and on expanding in emerging economies.

Suzuki later accused its German partner of withholding hybrid technology it had promised to share and demanded the return of the 19.9% stake.

Volkswagen complained about Suzuki's purchase of diesel engines from Fiat, Reuters said.