* Oil below $66 a barrel, at new 16-month lows
* OPEC meets, analysts expect 1-1.5 million bpd cut
* European, Asian stock markets tumble
(Recasts, adds analyst comment, upates prices, previous PERTH)
LONDON, Oct 24 (Reuters) - Oil fell below $66 a barrel on Friday, to new 16-month lows, pressured by gloom across all markets about a global economic downturn that could reduce the impact of any cut in oil output from OPEC.
Ministers of the Organization of the Petroleum Exporting Countries began an emergency meeting in Vienna on Friday that could decide to reduce output by at least a million barrels. [
]U.S. light crude for December delivery <CLc1> was down $2.68 at $65.16 a barrel by 0844 GMT, erasing earlier gains.
London Brent crude <LCOc1> was down $2.56 at $63.36.
"We believe this week will mark the start of a new quota reduction cycle by OPEC and it will continue through 2009," Deutsche Bank analyst Michael Lewis said in a note.
"However, we believe production cuts will not rescue the oil price," he said. "We target WTI (U.S.) crude oil prices hitting $50 a barrel next year."
Oil has plunged more than 50 percent from its record high above $147 in July, as demand has dropped in the United States, the world's biggest energy consumer and other industrial countries.
OPEC ministers have agreed the oil market is oversupplied, but there are differences over the size of a potential cut.
The group is considering two supply cut options: a 1 million barrel per day cut now and a review of this in December, or an immediate cut of 1.5 million bpd, an OPEC delegate told Reuters.
Analysts polled by Reuters anticipate OPEC will reduce output by between 1 million and 1.5 million barrels per day. [
].Investor pessimism about the world economy was highlighted by sharp falls in European and Asian stocks, led by around a 10 percent drop in Japan's Nikkei average <
>.Even gold, a traditional safe haven, was down 4 percent as the U.S. dollar rose.
Bleak outlooks from world car makers and a barrage of job cuts by major U.S. companies has provided evidence the financial crisis is spilling over into the real economy.
"If it wasn't for an expected OPEC cut, there is a strong possibility that oil prices would be falling a lot more considering how poorly Asian stocks are performing," said David Moore, a commodities strategist at the Commonwealth Bank of Australia. (Reporting by Jane Merriman in London and Fayen Wong in Perth, editing by Anthony Barker)