Formosa Petrochemical : Taiwan's Formosa issues rare U.S. crude purchase tender - sources

SINGAPORE (Reuters) - Taiwan's Formosa Petrochemical Corp has joined other Asian refiners in seeking U.S. oil supplies by issuing a rare tender to buy sour crude from the United States, four industry sources said on Wednesday.

The Taiwanese refiner last imported U.S. crude three years ago.

Formosa's tender comes as the arbitrage window for U.S. crude exports to Asia opened briefly last week, the sources said. South Korean and Indian refiners have bought sour crude grades such as Mars for delivery in October and November, they said.

"Mars seems cheap last week," one of the sources said.

Formosa sought 1 million barrels of U.S. sour crude for delivery between Oct. 20 and Nov. 20, the sources said.

The company did not award the tender in the end as offers were too expensive, they said.

The reopening of the arbitrage, which had been tightly shut for the past two months, has added downward pressure on prices of competing grades from the Middle East, the sources said.

For example, Iraqi Basra crude loading in August remained unsold and their spot differentials have flipped into discounts, they said.

(Reporting by Florence Tan; editing by Michael Perry and Jason Neely)

By Florence Tan