DETROIT, USA - UNITED States auto sales plunged in June to a 15-year low, but a month-end clearance sale helped General Motors retain its No. 1 spot and steer clear of the wipeout many had feared, sending its shares higher.

Record gas prices and declining trade-in values for big trucks and SUVs hit truck sales hard while major automakers, including Toyota Motor, struggled to keep up with demand for some popular smaller cars and hybrids.

GM was the industry's main surprise after a sale featuring zero per cent financing for six years allowed the US automaker to avoid losing sales leadership in the month to Toyota.

Equally damaging, sales of Toyota's hybrids including the market-leading Prius hybrid dropped 27 per cent as dealer inventory ran short of demand.

'GM was better than expected, and it looks like Toyota missed a big opportunity in the month,' said Mr Jesse Toprak, an analyst with industry-tracking website Edmunds.com.

Ford Motor sales were down 28 per cent, while Chrysler sales fell 36 per cent, the weakest result in the industry.

Now controlled by Cerberus Capital Management, the privately held automaker relies on light trucks for almost 70 per cent of its sales.

By contrast, Honda Motor, which boasts the most fuel-efficient vehicle line-up among major automakers, bucked the downturn and posted a 1 per cent sales gain.

Sales for Nissan Motor dropped 18 per cent.

The sales rate for light vehicles dropped to 13.6 million units on an annualised and seasonally adjusted basis, down from 15.7 million a year earlier, according to tracking firm Autodata. It was the weakest month since August 1993.

Most analysts and major automakers now expect full-year US sales to end up near 15 million units, down from 16.15 million in 2007 because of the devastated US housing market, high gas prices and weak consumer confidence.