Brent crude futures were down 30 cents at $76.20 a barrel by 12:16 p.m. EDT (1616 GMT). US West Texas Intermediate (WTI) crude futures fell 49 cents to $67.28 per barrel.

For the week, WTI was set to lose more than 3.5 percent, and Brent was on track to fall 1.6 percent.

Oil prices had posted gains early in the week as the approach of Gordon forced the closure of Gulf of Mexico oil platforms and threatened refineries on the Gulf Coast.

"The market got too juiced up before the tropical storm...a lot of the weakness in the week (since) has been unwinding from that," said Phil Flynn, analyst at Price Futures Group in Chicago.

The storm ultimately weakened and moved away from oil-producing areas and energy companies restarted operations shut-in as a precautionary measure.

The dollar rose against a basket of other currencies after a report showed US job growth surged in August and that wages notched their largest annual increase in more than nine years.

The jobs data raised concerns about the possibility of faster interest rate hikes, which in turn pressured equities markets. The pan-European STOXX 600 had its worst weekly performance since the end of March, while emerging market stocks dropped 3.2 percent.

US oil prices were also still weighed down by disappointing inventory data from the Energy Information Administration on Thursday, analysts said.

US crude inventories last week fell 4.3 million barrels to 401.49 million barrels, the lowest since February 2015, the EIA data showed.

But that data was offset by a rise in refined product stocks coupled with relatively weak demand for fuel during this summer's US driving season - when consumption normally peaks.

Gasoline stocks rose 1.8 million barrels, while distillate stockpiles climbed 3.1 million barrels, the EIA said.

"This bears all the hallmarks of a disappointing summer driving season. As a result, the alarm bells are now ringing that a gasoline glut will persist for the foreseeable future," Stephen Brennock of London brokerage PVM said.

Meanwhile, US sanctions against major oil producer Iran are fueling expectations of a tighter market.

"The main driver of oil prices, in our view, remains the reimposition of US ... sanctions against consumers of Iranian oil," Standard Chartered said this week.

Washington has indicated it may offer temporary sanction waivers to allied countries that are unable to cease imports immediately from Iran.