Saudi Arabia's Rabigh Refining and Petrochemical Co (PetroRabigh) swung to a first-quarter net loss, it reported on Wednesday, as its earnings were impacted by the plant's gradual restart after a period of maintenance at the end of last year.

The firm, a joint venture between Saudi Aramco and Japan's Sumitomo Chemical, made a loss of SR32.7 million ($8.7 million) in the three months to March 31, it said in a bourse statement.

This compares with a net profit of SR205.4 million ($54.7 million) in the year-ago period.

PetroRabigh shut its refining and petrochemical complex for 50 days in the previous quarter, restarting its operations in stages during December.

The company said the gradual return of operations at the plant meant that sales volumes during its transition period were reduced, resulting in the negative performance in the first quarter.

This was even as the price of crude oil and petrochemical products increased during the quarter, PetroRabigh said in its bourse filing.

PetroRabigh's earnings have been hit hard by falling product prices, like many petrochemical firms in the kingdom, as they are closely tied to slumping oil prices. Saudi producers have also benefited from subsidised energy and feedstock costs, so lower crude prices compress their margins.

The latter is changing though after the government hiked energy and feedstock costs late last year; PetroRabigh said the move will have a negative financial impact of SR300 million ($80.01 million). - Reuters