General Motors chief executive Rick Wagoner said on Monday that GM's partnerships with Japanese car makers had not always worked as planned, but they had been profitable and work would expand, Reuters reported.

The news agency noted that, over the years, GM has had to write off its stake in Isuzu Motors, Japanese sales of its Chevrolet Cruze made by Suzuki have been weaker than expected, and its stake in Subaru parent Fuji Heavy Industries has lost value.

"Everything doesn't always work out as you plan," Wagoner told Reuters at a press briefing with GM's Japanese partners in Tokyo ahead of the start of this week's bi-annual motor show, adding: "Actually, we've gotten, frankly, very good returns. We feel like these are good investments for our shareholders."

GM and the three Japanese firms will work together in the future to broaden their relationship, Wagoner reportedly said.

As part of GM's strategy to expand its Chevrolet line in Japan, GM will sell at Suzuki dealerships next year two sedans made in South Korea by GM Daewoo Auto & Technology Co., which is 45% owned by GM and 15% owned by Suzuki, Reuters said.

The Chevrolet Epica mid-size car and the Optra large car, based on GM Daewoo's Lacetti and Magnus cars, will be the latest vehicles exported from GM Daewoo, the one-year old car maker formed from the ashes of bankrupt Daewoo Motors, Reuters noted.

The news agency noted that GM has tried, and failed, for years to crack the tough Japanese market, often with American-made cars.

"Over the years, I've announced a lot of different strategies, and I think this is the one that has the highest probability of working, which is recognising that we have to rely on some local products," Wagoner reportedly said, adding: "We have to face the fact that, by and large, the products sold here are quite different than those that are demanded by US consumers."

Reuters said the project also helps GM Daewoo, which has aggressively expanded exports to overseas markets from South Korea to fill excess capacity as it struggles to return to profitability.

Wagoner also told Reuters that GM is also talking with Subaru parent Fuji Heavy Industries (FHI) on how they can expand their relationship. Fuji will next spring begin manufacturing and selling the Saab 9-2X, a turbo-charged sports sedan based on the Subaru WRX all-wheel drive car, and Wagoner reportedly said that Saab and Subaru are also working together on other projects.

"Going forward, we believe that the collaboration of FHI and Saab will be the cornerstone of the GM-FHI [arrangement]," Wagoner told Reuters, adding: "And beyond that, we're going to continue to explore new co-operation in powertrains, overseas distribution and manufacturing."

Fuji chief executive officer Kyoji Takenaka told Reuters that working with Saab will help Subaru's desire to become a premium brand in the market.

GM is also working with Isuzu in China to see where they can collaborate on the growing commercial truck segment, Wagoner told Reuters, adding that the two companies will announce more details later, when they finalise a plan.