The OPEC+ alliance of oil-producing countries has postponed its next meeting on output policy to Dec. 5 from Dec. 1 to avoid a conflict with another event, OPEC said on Thursday.

A summit of Gulf Arab countries is due to be held in Kuwait City on Dec. 1 which several OPEC+ ministers plan to attend, OPEC said in a statement.

"Sunday does not suit everyone," a source had told Reuters before the official announcement.

Top OPEC+ ministers have held talks ahead of the meeting. OPEC+ sources have said there will be discussion over a further delay to oil output increases due to start in January.

Saudi Energy Minister Prince Abdulaziz bin Salman, de facto head of the Organization of the Petroleum Exporting Countries (OPEC), on Wednesday had a phone call with Russian Deputy Prime Minister Alexander Novak and Kazakh Energy Minister Almasadam Satkaliyev while in Kazakhstan on an official visit.

Iraq, Saudi Arabia and Russia held talks in Baghdad on Tuesday.

OPEC+, which comprises OPEC and allies led by Russia pumps about half the world's oil. The group aims to gradually unwind oil production cuts through 2025 which it introduced to help support prices.

However, a slowdown in Chinese and global demand and rising output outside the group pose hurdles to that plan.

OPEC+ on Nov. 3 again postponed its first output hike which had been set for December by one month.

OPEC+ members are holding back 5.86 million barrels per day (bpd) of output, or about 5.7% of global demand.

Their planned first increase of about 180,000 bpd - a fraction of the total - is due to be made by the eight members involved in the group's most recent cuts.

(Reporting by Vladimir Soldtakin in Moscow and Ahmad Ghaddar in London; additional reoprting by Angela Christy in Bengaluru; writing by Yousef Saba in Dubai; editing by David Goodman and Jason Neely)