"Uncertainty remains about the swift incorporation of Libyan volumes into the global oil market. We remain sceptical given the operational, legal and contractual issues at play," Barclays Capital analysts said in a client note. World oil prices edged higher after Libyan rebels seeking the ouster of leader Moamer Qadhafi gained control of key ports, easing supply fears. Traders weighed the potential impact of a move by Qatar to help Libyan rebels resume crude oil exports that have dwindled to a trickle amid the unrest. Qatar, which on Monday became the first Arab country to recognize the rebel Provisional Transitional National Council as the sole legitimate representative of Libya, signed a contract to market Libyan oil exports, a rebel council official said. At an international Libya summit Tuesday in London, British Foreign Minister William Hague said that Qatar had agreed to facilitate the sale of Libyan oil. Libya produced 1.7 million barrels of oil per day before the unrest. Commerzbank analysts said that "the hopes of Libyan oil shipments normalizing soon are exaggerated." They noted the security situation in Libya remained tense, "which is making it difficult for oil workers to return to production sites."