Oil tumbled below $80 a barrel for the first time in eight months on weak economic data that increased concern that demand will slow with supplies at the highest level in almost 22 years.

Futures dropped as much as 2.3 percent as manufacturing slumped in the U.S., Europe and China and more Americans than forecast filed applications for unemployment benefits. Sales of previously owned U.S. homes declined in May. U.S. oil stockpiles rose last week to the most since 1990, the Energy Department reported yesterday.

Crude futures for August delivery on the New York Mercantile Exchange fell to $79.25, the lowest intraday level since Oct. 6. Prices have slumped 27 percent from this year’s settlement high of $109.77 on Feb. 24.

Brent oil for August settlement decreased $1.82, or 2 percent, to $90.87 a barrel on the London-based ICE Futures Europe exchange. The European benchmark contract was at a premium to West Texas Intermediate of $11.15 after closing at $11.24 yesterday, the lowest level since January.