The world"s top oil exporter, Saudi Arabia, has cut February"s official selling price for all grades of crude it is selling to Asia by at least $1 a barrel, three sources with knowledge of the matter said on Thursday. State oil giant Saudi Aramco set the February OSP for Arab Light crude at $2.20 a barrel above the average of Oman/Dubai quotes, down $1.10 from the previous month, they said. The February OSP for the flagship crude is the lowest in three months. Saudi Aramco had been expected to make deep price cuts for February after Middle East benchmarks and spot prices slumped last month. However, the sources said the price cuts were still smaller than industry expectations. For example, the OSP for Arab Light was expected to have fallen by at least $1.30 a barrel, a Reuters survey showed.