The Organization of Petroleum Exporting Countries (OPEC) is unlikely to adjust its official production ceiling of 27.5 million barrels per day (bpd) during its upcoming meeting in June, its president Sheikh Ahmed Fahed al-Sabah said Sunday, dpa reported. Speaking to reporters on the sidelines of a conference organized in Kuwait by OPEC and the International Energy Agency (IEA), Sheikh Ahmed also said that market prices were finally beginning to stabilize. The cartel would consider 40 dollars per barrel an acceptable price for the basket of OPEC crudes, he said. Strong inventory figures that emerged from the United States last week mainly pushed U.S. crude prices down ending the week last Friday at 48.67 dollars per barrel. OPEC-10 and Iraq, which is not bound by a quota, has also been pumping at a rate estimated at nearly 30 million bpd to meet demand as well as anticipated increased demand for the fourth quarter of 2005, said Sheikh Ahmed, who is also Kuwait's Energy Minister. --More 2221 Local Time 1921 GMT