Montana leak may alter Exxon safety reviews: exec

NEW YORK (Reuters) - The president of Exxon Mobil Corp's pipeline unit said the company still does not know the cause of a pipeline leak that has sent about 1,000 barrels of oil into Montana's Yellowstone River, but that it may change the way it conducts pipeline safety reviews.

"This will give us additional information to think about when we consider doing risk assessments on any line that has a river crossing anywhere in the country," Gary Pruessing, president of ExxonMobil Pipeline Co said during a press conference in Laurel, Montana.

Exxon does not own any other underwater pipelines in the region, he said.

On Sunday, Exxon said it shut down a crude oil pipeline after as many as 1,000 barrels of crude oil leaked into the Yellowstone River in Montana. The oil company has estimated that from 750 to 1,000 barrels of oil were released before the leak was detected.

One barrel of oil is equivalent to 42 gallons (163 liters).

The leak followed a company shutdown of the pipeline in May after the city of Laurel had safety concerns due to the rising levels of the river from rain and runoff.

"At the time we shut down the line ... and went down and did a further risk assessment to make sure the site, based on the technical knowledge we had, was something we'd feel comfortable to run," Pruessing said. "We restarted the line feeling like we had a safe operation."