Algerian Energy and Mines Minister and Organiztion of the Petroleum Exporting Countries (OPEC) President Chakib Khelil (C) arrives to give a press conference at the pro-governmental newspaper El-Moudjahid on March 11, 2009 in Algiers. Oil prices fell slightly on March 11 as the market geared up for the release of key data on US energy stockpiles ahead of OPEC's weekend meeting to discuss crude output levels.