UPDATE: Dealer Supplies of Unsold Cars Surge in U.S.

Inventories of unsold vehicles in the U.S. are near record highs after climbing 39% in the past year to 4.1 million units, according to Automotive News.

The glut is being led by General Motors Co., whose dealers added more than 354,000 cars and light trucks—up 30% in 12 months—to their supplies. AN says inventories by all other carmakers grew 3%, or 81,500 units, over the same period.

New-car sales in the U.S. have been slipping below year-ago levels since January. Sales through the first half of 2017 totaled 8.45 million, down 2% from the same period last year, according to Autodata Corp.

GM said earlier this year it was deliberately stockpiling to offset lost production when several U.S. factories retool this summer. In June, The company expected dealer inventories to shrink to a 90-day supply from 101 days by July 1. Instead, stocks rose to 105 days. GM predicts its dealer inventories will shrink to 70 days by year end, slightly above the 60-day inventory considered normal.

The current U.S. glut is second only to the record 4.2 million units of unsold vehicles accumulated by carmakers in mid-2004, according to AN. The newspaper calculates that industry-wide supplies rose by five days to 74 days in June. Seven of the U.S. market’s largest sellers gained 4-7 days of inventory in the past month.