DUBAI, Jan 18 (Reuters) - PetroRabigh 2380.SE swung to a net profit of 183 million riyals ($48.8 million) in the fourth quarter of last year from a loss of 1.01 billion riyals in the same quarter a year earlier, the company said on Wednesday.

The firm, a joint venture between Saudi Aramco IPO-ARMO.SE and Japan's Sumitomo Chemical 4005.T , cited relatively stable operations and the positive impact on inventory valuation of feedstock price increases for the swing to profit.

The firm said in July that the financial impact of a temporary stoppage of its ethane cracker at the time would be about 350 million riyals spread across its second and third-quarter earnings for 2016.

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.

The company said on Dec. 29 it had chosen HSBC Saudi Arabia as a financial adviser for a 9.26 billion riyal rights issue to fund its expansion. ($1 = 3.7493 riyals)

(Reporting by Davide Barbuscia; Editing by Keith Weir) ((Davide.Barbuscia@thomsonreuters.com;))