LONDON - Oil prices dipped on Friday as traders sat tight before US employment figures and following recent gains spurred by positive economic data in energy guzzlers the United States and China.

Prices have won support in recent days also on growing concerns about supply disruptions in the Middle East and Africa, traders said.  Brent North Sea crude for delivery in September fell 16 cents to $109.38 a barrel.

New York's main contract, West Texas Intermediate for September, shed 11 cents to $107.79 a barrel.

"Crude oil prices slid lower... due to some profit taking as investors remain cautious ahead of the release (Friday) of the important US non-farm payroll data," said Myrto Sokou, senior research analyst at Sucden brokers. "Brent fell slightly after surging above the $110 level yesterday for the first time since April 2013, showing strong upside momentum after robust PMI manufacturing data from the US and eurozone," she added.

China's official PMI also showed a surprise increase -- a rare piece of positive economic data from the Asian economic power, which has been slowing in recent months.

"Crude prices have reacted to global growth, with both US and China the top two largest users of crude," Kelly Teoh, market strategist at IG Markets Singapore, said in a note to clients.

"It is clear the Chinese government is doing what it can to keep the economy going and it will not allow growth to miss the seven percent target," Teoh said.

Investors are keeping a close watch also over potential supply disruptions in the Middle East and Africa.

"Protests in Libya's oilfields, insurgents targeting Iraq's pipeline, technical problems and oil thefts in Nigeria (have) brought about worries about the availability of supplies," said Lee Chen Hoay, investment analyst at Phillip Futures.