DUBAI, Oct 23 (Reuters) - Saudi Basic Industries Corp 2010.SE (SABIC) said on Sunday that it started commercial operations the previous day at the polybutadiene industrial rubber part of its KEMYA joint venture with a unit of Exxon Mobil XOM.N .

The Saudi firm, one of the world's largest petrochemicals groups, added in a bourse filing that it had also begun trial operations at the ethylene propylene diene monomer unit of the KEMYA complex on Friday.

The financial impact of the start of commercial operations at the polybutadiene unit would be reflected in its fourth-quarter earnings, while the ethylene propylene diene monomer business would likely reach full capacity in the first quarter of 2017.

Al-Jubail Petrochemical Company (KEMYA) rubber plant cost $3.4 billion and is a joint venture between SABIC and Exxon Chemical Arabia, a subsidiary of Exxon Mobil.

The project will supply over 400,000 metric tonnes per year of rubber, thermoplastic polymers and carbon black for domestic markets and for export to Asia, according to the statement.



(Reporting by Celine Aswad and Maha El Dahan; Writing by David French; Editing by Richard Pullin) ((davidj.french@thomsonreuters.com; +971 4 362 5864; Reuters Messaging: davidj.french.thomsonreuters.com@reuters.net))