SINGAPORE, Mar. 11 (CNA) - Saudi Aramco, the world's top crude exporter, plans to reduce Arab Heavy crude supply to term customers in Asia in April due to oilfield maintenance, two sources with knowledge of the matter said on Monday.

The producer will maintain April-loading for other crude grades, one of the sources said.

The reduction comes after the Organization of the Petroleum Exporting Countries and their allies, a group known as OPEC+, decided early this month to extend voluntary oil output cuts of 2.2 million barrels per day into the second quarter.

Saudi Aramco notified Asian customers of their April crude allocations, days after releasing the official selling prices for the same month.

The producer had unexpectedly raised prices for heavier grades in April, which narrowed the price gap with lighter grades.

It was not immediately clear how much Arab Heavy crude supply will be reduced by and which oilfield will be shut for maintenance.

Saudi Aramco did not immediately respond to a request for comment outside office hours.