General Motors rolled out fresh incentives on Monday in an attempt to staunch plummeting sales of gas-guzzling sport-utility vehicles, pick-up trucks and other slow-selling models.

The Detroit-based carmaker said it would offer interest-free financing for up to six years – an unusually long period for such promotions – on vehicles such as the Chevrolet Tahoe and GMC Yukon SUVs, the big Hummer and the Chevrolet Silverado pick-up.