VIENNA, Dec. 18 (Xinhua) -- The Organization of Petroleum Exporting Countries (OPEC)'s weekly average crude oil prices dropped 1.47 U.S. dollars to 57.59 dollars per barrel last week,the cartel's secretariat said on Monday.

    In the first four days last week, the crude oil prices fluctuated between 57 and 57.74 dollars. The price went up by 0.96 dollars on Friday after the meeting of OPEC members on Thursday in Abuja, Nigeria.

    According to its monthly report on Monday, OPEC oil supplies in November was at 28.8 million barrels per day (bpd).

    OPEC expects the global demand to grow by 1.3 million bpd in 2007, and non-OPEC supplies to grow by 1.8 million bpd reaching 53 million bpd, the report projected.

    "Risks for oil demand appear to be more weighted on the downside, given the dangers on global economic growth emanating from a visibly weakening U.S. economy," said the oil cartel.

    Due to the forecast of world oil demand growth in 2007 and the possible market imbalances, OPEC decided to reduce its daily oil production by 500,000 barrels, starting from Feb. 1, 2007, at its meeting in Abuja.

    However, some market analysts say that the promised cut from February is unlikely to be carried out.