General Motors reportedly will stop production of the Chevrolet Volt range extender EV for the northern hemisphere summer to reduce about seven months of unsold stock and smooth the way for the next generation model.

GM has sold about 70,000 Volts since sales started in 2010, far below initial company forecasts, according to the Wall Street Journal.

Production of the current model, which costs from US$34,000 before federal government tax credits, will halt early in May, the report said. The second generation Volt, previewed at the Detroit show in January, will go into production at the end of summer.

The WSJ said Volt first quarter 2015 sales fell well to 1,874 units, well behind Nissan’s all-electric Leaf sales of 4,085 in the US. Volt stocks are enough to last 210 days, or until November, at their March sales pace, according to researcher Autodata. Car makers generally like to have about 60 days of inventory at US dealers, the WSJ added.

The Volt was also sold as a Holden in Australia and, with a light restyle, as the Opel/Vauxhall Ampera in Europe and the UK.

Analysts have said reviving consumer interest in the Volt is a top priority for GM as it prepares to release its all-electric Bolt sedan.

Volt development required over US1bn but the model failed to generate a fraction of the buzz that Tesla achieved with its pricier Model S luxury electric car or Toyota with its Prius family of hybrids, the WSJ said.