* U.S. adds two oil drilling rigs this week - Baker Hughes
* North Dakota crude production rises in June
* U.S. crude drops to lowest since March 2009 intraday
* Brent crude September contract expired on Friday (Rewrites lead, updates prices to settlement)
By Robert Gibbons
NEW YORK, Aug 14 (Reuters) - U.S. crude oil edged higher after falling to a fresh 6-1/2-year low on Friday, posting a seventh weekly loss amid concerns over global oversupply, while Brent futures slipped as the front-month September contract approached expiration.
Data showing North Dakota crude oil production rose a second straight month in June helped pull U.S. crude off its session high, along with the stronger dollar and weaker-than-expected consumer sentiment.
“Producers don’t seem to want to blink,” said Gene McGillian, senior analyst at Tradition Energy in Stamford, Connecticut, commenting on the North Dakota data.
Producers in the United States added two oil rigs this week, a fourth straight week with additions, energy services firm Baker Hughes Inc said.
U.S. crude bounced early off a fresh 2015 low and then received a lift from data showing U.S. producer prices rose for a third straight month in July.
U.S. September crude settled at $42.50 a barrel, up 27 cents, and continued to seesaw in post-settlement trade. It reached $42.96 after falling to $41.35, the lowest front-month price since March 2009, and finished off more than 3 percent for the week.
Expiring Brent September crude fell 19 cents to settle at $49.03, but gained nearly 1 percent for the week, snapping a string of six weekly losses. Brent prices are well above the 2015 low of $45.19 from January, despite its recent slide.
Brent October crude also fell.
Money managers cut their net long U.S. crude futures and options positions in the week to Aug. 11 to the lowest level since 2010, the U.S. Commodity Futures Trading Commission said.
U.S. crude futures were pressured this week as refinery outages dampened demand and bulging inventories amplified concerns about a global supply glut.
The largest of the affected refineries, BP’s 413,500-barrels-per-day (bpd) Whiting, Indiana, facility shut two-thirds of its capacity for repairs that could last a month or more.
Commerzbank analyst Carsten Fritsch said he did not expect an accelerated drop in prices, but rather “a slow grind lower” as long as the Whiting refinery was out of service.
The U.S. refinery problems come as the seasonal autumn refinery maintenance approaches at the end of the summer driving season.
Brent felt pressure from weak economic growth data from Europe and both crude contracts have been weighed down by concerns about No. 2 oil consumer China’s sputtering growth.
Goldman Sachs said a weaker Chinese currency was putting downward pressure on all commodity markets, signalling a turn for the worse for global economic conditions. (Additional reporting by Lisa Barrington in London; Editing by Marguerita Choy)