VIENNA (Reuters) - A key monitoring committee of OPEC and its allies, including Russia, agreed on Wednesday on the need to cut oil output in 2019, two sources familiar with the decision said, adding that debates about volumes and the baseline for cuts were ongoing.

The committee, known as the Joint Ministerial Monitoring Committee that includes Saudi Arabia and Russia, met in Vienna on Wednesday, a day before the meeting of members of the Organization of the Petroleum Exporting Countries.

Saudi Arabia has been seeking to persuade Russia to cut oil production substantially with OPEC next year in a bid to halt a decline in the price of crude and prevent another global glut.