* Iran, Venezuela, Libya, Ecuador want cartel to cut output
* Saudi Arabia reported to be reluctant to commit to cuts
* German, U.S. data supportive, China figures weigh (Updates prices, adds analyst comment; paragraphs 1, 4-5)
By Ahmed Aboulenein and Jack Stubbs
LONDON, Nov 25 (Reuters) - Brent crude oil prices steadied around $80 a barrel on Tuesday ahead of a key meeting of OPEC oil producers to decide on production levels for next year.
Oil market watchers are divided on the outcome of Organization of the Petroleum Exporting Countries meeting this Thursday in Vienna. Predictions range from a large production cut to revive prices, to a small reduction, or none at all.
Oil prices have fallen by almost a third since June and are far below what most OPEC members and rival producers such as Russia need to balance their budgets.
Several OPEC members want the group to cut production dramatically to ease a global supply glut, but Saudi Arabia, the biggest exporter, appears reluctant to endorse a big cut.
"This is arguably the most important OPEC meeting since the 2008/09 crisis," Virendra Chauhan, an oil analyst at London-based consultancy Energy Aspects, told Reuters Global Oil Forum. "Claims of advanced knowledge about a cut and its size are a guesstimate at best."
Brent was trading at $80.13 a barrel by 1140 GMT, up 45 cents, while U.S. crude was 30 cents higher at $76.08.
"The rapid growth now being achieved in non-OPEC production means it faces the risk that even a large cut to supply may not be enough to support prices and could simply result in lost market share and revenue," Barclays Bank analysts said.
"Saudi Arabia's response so far to falling oil prices is an acknowledgment that it is less able to influence oil prices than at any time over the past decade," they added in a note.
Economic data were mixed for oil.
Europe's biggest economy, Germany, posted modest growth in the third quarter to avoid recession, data showed on Tuesday.
Preliminary U.S. data, to be published at 1330 GMT, is likely to show that the country's GDP increased at a 3.3 percent annual pace.
But a gradual slowdown in China, the world's biggest energy consumer, weighed on oil.
Credit ratings agency Moody's said on Tuesday a steep economic slowdown in China could hurt sovereign borrowers with a heavy reliance on oil exports to China, such as Oman, Saudi Arabia and Kuwait. (Additional reporting by Henning Gloystein in Singapore; editing by Susan Thomas)
