(Reuters) - Oil prices fell for a third day on Friday, on course to end the week lower, as investors focused on expectations of higher supplies from Libya and the broader OPEC+ group of oil exporters.

Brent crude futures fell 57 cents, or 0.8%, to $71.03 per barrel by 0036 GMT, while U.S. West Texas Intermediate crude futures were down 58 cents, or 0.9%, to $67.09 a barrel.

On a weekly basis, Brent crude was set to shed about 4.6%, while WTI is on track to slide 6.6%.

"The big-ticket items on the markets radar this week have been Libya and OPEC+," analysts at FGE Energy told clients on Thursday.

Rival factions staking claims for control of the Central Bank of Libya signed an agreement to end their dispute on Thursday. The dispute had caused a sharp reduction in oil production and exports in the country, with crude exports down to 400,000 barrel per day (bpd) this month, from over 1 million barrels last month.

The agreement could see more than 500,000 bpd of Libyan supply return to markets, ANZ Bank analyst Daniel Hynes said.

Separately, the Organization of Petroleum Exporting Countries (OPEC), and its allies, a group known as OPEC+, are currently cutting oil output by a total of 5.86 million bpd but it plans to reverse 180,000 bpd of those cuts in December.

A media report on Wednesday claimed the previously announced reversal is due to Saudi Arabia's decision to abandon a $100 oil price target and gain market share, causing oil prices to slide by 3% in the previous session.

Saudi Arabia, the de facto leader of OPEC+, has repeatedly denied targeting a certain oil price, and sources at the wider group told Reuters that the plans to raise output in December do not represent any major change from existing policy.

Still, the report has set off renewed speculation about a battle for market share at a time that investor sentiment was already at record lows, FGE noted.

"All in all, it is evident that oil markets remain very cautious about global oil balances in 2025 and what OPEC+ "should do", with the recent bearish mood being underscored by the record low net length across ICE Brent contracts for managed money positioning," FGE said.

(Reporting by Shariq Khan in New York; Editing by Christian Schmollinger)