West Texas Intermediate and Brent crudes dropped after weaker-than-estimated U.S. jobs growth in August and as Ukraine and pro-Russian separatists agreed to a cease-fire.

Both benchmark oils are poised for weekly declines. U.S. employers added the fewest number of jobs this year in August, Labor Department data showed today. The two sides agreed to stop fighting at 6 p.m. local time today, Heidi Tagliavini, a representative of the Organization for Security and Cooperation in Europe, said after talks in Minsk, Belarus. Russia is the world's largest energy exporter.

"The jobless report was disappointing," Kyle Cooper, director of research with IAF Advisors and Cypress Energy Capital Management in Houston, said by phone. "It's evidence that the economy isn't going gangbusters. This raises demand concerns, especially when economies elsewhere are looking weak."

WTI for October delivery slipped 85 cents, or 0.9 percent, to $93.60 a barrel at 10:58 a.m. on the New York Mercantile Exchange. Prices are down 2.5 percent this week and 4.9 percent this year.

Brent for October settlement dropped 87 cents, or 0.9 percent, to $100.96 a barrel on the London-based ICE Futures Europe exchange. The contract is down 2.2 percent this week. The European benchmark crude traded at a $7.36 premium to WTI, compared with $7.38 at yesterday's close.