General Motors could finalize the sale of its German auto unit Opel as early as this week, the U.S. automaker's CEO Fritz Henderson said Tuesday.

Henderson, visiting China for the first time since GM was restructured last summer, was also upbeat about the prospects for the sale of the company's Hummer unit to Chinese buyer Sichuan Tengzhong Heavy Industrial Machinery Corp., which is still awaiting Chinese government approval.

General Motors' sale of its Opel unit could be finalized as early as this week, GM CEO Fritz Henderson said Tuesday. (Michael Probst/Associated Press

Despite labour union objections over possible job losses, the sale of GM's Opel and Vauxhall units to Canadian autoparts supplier Magna International Inc., which along with Russia's state-owned Sberbank acquired a 65 per cent stake in the German-based Opel from General Motors Co. last month, is expected to go ahead, Henderson told reporters.

"It's quite possible that you'll see documents signed this week," he said.

Though remaining issues are being worked out at the government level, Henderson said for the new arrangement to succeed the business would have to be restructured.

"We're 35 per cent of the business and we want it to succeed. In order to be successful we need to take a significant amount of cost out of the business," he said.

GM, which spent 40 days in bankruptcy protection during the summer and has received about $50 billion in U.S. government aid, also plans to sell its Saab brand and scrap Pontiac and Saturn as it tries to streamline its operations.

GM signed a much-anticipated deal to sell its off-road vehicle unit Hummer to Sichuan Tengzhong on Friday. The deal gives Sichuan Tengzhong an 80 per cent stake in the company, while Hong Kong investor Suolang Duoji, who indirectly owns a big stake in Tengzhong through an investment company, will get 20 per cent. The investors will also get Hummer's nationwide dealer network.

Henderson would not comment on the sale price, said by a person close to the deal to be around $150 million — much lower than the $500 million it was valued at in GM's bankruptcy filing — apart from saying the company was "satisfied."

Henderson denied reports that while in China he would meet with authorities to push for the deal's approval, saying that while GM would support Sichuan Tengzhong it was up to the Chinese buyer to win needed government approvals.