LONDON, Nov 21 (Reuters) - Prominent commodities fund manager Andy Hall will participate in an OPEC shale oil workshop, three OPEC sources said, as the exporter group seeks a wider range of views on the market outlook before a key meeting to set policy.

Hall is among the speakers scheduled to attend the workshop at OPEC's Vienna headquarters on Wednesday, which will gather a number of OPEC officials including Secretary General Mohammad Barkindo, the sources said.

"He will participate in our workshop tomorrow," one of the sources said.

The Organization of the Petroleum Exporting Countries, plus Russia and nine other producers, are cutting oil output by about 1.8 million barrels per day until next March in an attempt to eradicate a supply glut.

The cut has helped oil prices LCOc1 rise this year to almost $65 a barrel, the highest since 2015, after falling from above $100 in mid-2014 to a 12-year low near $27 in early 2016, pressured by excess supply from shale producers and OPEC.

OPEC, the sources said, is keen to hear the views of Hall, who is famous for being an oil bull, on the outlook. British-born Hall has traded oil for more than three decades and once earned a $100 million bonus from Citigroup C.N .

Hall was reported in August to have closed his main hedge fund after losses. He could not immediately be reached for comment on Tuesday.

OPEC and its allies meet on Nov. 30 and are widely expected to extend their deal to cut production, which ends in March 2018, further into next year.

(Editing by Louise Heavens) ((alex.lawler@thomsonreuters.com; +44 207 542 4087; Reuters Messaging: alex.lawler.reuters.com@reuters.net))