RIYADH, Aug 28 (Reuters) - Emirates National Oil Company (ENOC) has awarded the last of three contracts for its $1 billion refinery expansion project to Dubai-based Overseas-AST, according to a statement on state news agency WAM on Monday.

The contract is for the construction of pipelines connecting the Jebel Ali refinery's processing units, storage tanks and berth facilities, the statement said.

The pipelines will carry jet fuel, isomerate and light and heavy naphtha.

The expansion, expected to finish by the fourth quarter of 2019, will increase production capacity to 210,000 barrels per day (bpd) from 140,000 bpd.

(Reporting by Katie Paul, editing by Louise Heavens) ((Katie.Paul@thomsonreuters.com;))