General Motors Corporation's (GM) planned launch of the closely watched Chevrolet Volt in 2010 will remain 'a stretch' even though the automaker has not hit any snags in its development of the rechargeable electric car, the automaker's chief executive said on Tuesday.

GM Chief Executive Rick Wagoner also said the automaker's initial tests of a new-generation of lithium-ion batteries needed to power the Volt had been 'favourable.'

'From the beginning, going for 2010 was a stretch, and it's still a stretch, but we're putting resources like crazy into it and we haven't seen anything yet that says we've hit a glitch on it,' Wagoner told reporters on the sidelines of the Consumer Electronics Show in Las Vegas.

The Volt represents GM's bid to beat rival Toyota Motor to the market with a hybrid vehicle that can be recharged at a standard outlet and to win back consumers who have abandoned the Detroit-based automaker's brands because of concern about fuel economy and the environment.

 When Wagoner said on Thursday there was no guarantee that GM could meet the timetable for a launch of the highly-anticipated Volt by 2010, the remarks prompted headlines and coincided with a drop in GM shares.

But the GM chief executive said his view that there was a risk that GM could fail to meet its ambitious launch target had not changed from the beginning of the Volt project.

'It's what we've been saying all along,' he told reporters in Las Vegas ahead of a keynote speech he was scheduled to deliver at the consumer electronics trade show.

Wagoner said the Volt development effort was far more complex than the usual process of turning a concept car into a production model, which typically takes three to four years.

In addition to the standard vehicle engineering, GM is working with suppliers to develop a new generation of lithium-ion batteries, which have been long used in consumer electronic devices such as cell phones, to power vehicles.

At the same time, GM engineers are scrambling to figure out how to run a whole range of vehicle features - from satellite radio to air conditioning - without cutting into the Volt's ability to run 40 miles on battery power alone as GM has planned.

GM engineers also are working out how to develop a first-of-its-kind liquid cooling and heating system for the Volt's battery-pack that will protect it from extreme cold and heat where battery performance suffers, executives said on Tuesday.

Wagoner added: "On the battery side, we're progressing very well, and we're basically pushing the technology needle to do everything we want to do from a technology that is emerging rather than developed."-Reuters