U.S. wholesale inventories (search) jumped unexpectedly in September as stocks of nondurable goods such as petroleum and groceries mounted, the government said on Friday.

Sales at the wholesale level also rose, boosted by demand for lumber and computer equipment, the Commerce Department (search) said.

Wholesale stocks climbed 0.4 percent in the month -- the sharpest rate of increase for inventories since March -- after a revised 0.1 percent drop in August. Analysts were expecting September inventories to climb 0.1 percent.

Sales gained 0.5 percent in September after a 0.2 rise in the preceding month.

The inventory-to-sales ratio (search), which measures the amount of time it takes to deplete supplies at the current sales pace, fell to 1.20 months, a record low after the preceding month's ratio was revised upward to 1.21 months.

Inventories of drugs, machinery, computer equipment and cars fell.