WASHINGTON (Reuters) - Stocks at U.S. businesses climbed to their highest level in a year in October, boosted by inventories on retailers' shelves, while sales climbed at their fastest pace since July, the government said on Friday.

"Retailers were building up stocks ahead of the holiday shopping period but only very modestly," said Mark Vitner, Wachovia Bank in Charlotte, N.C.

Inventories at retailers, manufacturers and wholesalers grew 0.2 percent in October to $1.134 trillion, the Commerce Department said.

That followed a rise of 0.6 percent in inventories during September and was more than expected by analysts, who forecast an increase of 0.1 percent.

Stocks at retailers were up a fairly modest 0.7 percent in October.

"If anything it looks like they didn't build up inventories enough as some of the more popular items have already sold out," said Vitner.

Inventories at merchant wholesalers fell 0.3 percent while manufacturers' stockpiles were unchanged.