Oil fell for a third day, extending its drop from the lowest close since 2009, as record supplies from Iraq and Russia bolstered speculation that a global glut that drove crude into a bear market will persist.

Crude oil dropped to the lowest level in more than five years Dec. 18 on concern a supply glut will worsen.

West Texas Intermediate oil dropped below $60 a barrel for the first time since July 2009 as Saudi Arabia questioned the need to cut output, signaling its priority is defending market share. Brent fell to a five-year low.

Two of the nation’s largest oil field service companies, Halliburton Co. and Baker Hughes Inc., agreed to combine operations, a move that company officials said will save an estimated $2 billion a year in expenses.

West Texas Intermediate oil fell below $90 for the first time in 17 months amid signs that supplies from Russia, Saudi Arabia and the U.S. are outstripping demand.

The Commerce Department opened the door to more U.S. oil exports as long as the crude is lightly processed, tempering the impact of a law that has banned most such shipments for the past 40 years.

The Obama administration said it plans to sell 5 million barrels of crude from the U.S. Strategic Petroleum Reserve in a test of the distribution system.

Diesel’s retail price will decline to $3.81 a gallon this year — 11 cents below last year’s average but 4 cents over last month’s projection, the Department of Energy reported.

The Organization of Petroleum Exporting Countries decided Dec. 4 to maintain the current crude oil production level until June in an effort to keep prices stable.