HOUSTON, Sept 10 (Reuters) - Energy pipeline operator

Enbridge ( ENB ) has pulled employees from several offshore

U.S. Gulf of Mexico platforms, the company told customers, as

Tropical Storm Francine advanced toward a landfall in Louisiana.

Francine has shut in oil and gas production at offshore

platforms operated by Chevron ( CVX ), Exxon Mobil ( XOM ) and

Shell. The first official measure of the storm's impact

on U.S. energy production will be released later on Tuesday by

U.S. regulator the Bureau of Safety and Environmental

Enforcement.

Enbridge ( ENB ), which manages an extensive network of offshore

pipelines funneling oil and gas to onshore plants, evacuated

staff from three offshore platforms. Operations are continuing

at each using remote operators, it said in notices to customers.

Staff were removed from South Marsh Island 76, Ship Shoal

207 and 332 platforms, the customer notices said. South Marsh

Island 76 connects a 1 billion cubic feet per day natural gas

offshore pipeline.

The Manta Ray Gas Gathering system declared force majeure at

its Green Canyon 158 Brutus receipt point and stopped receiving

natural gas, Enbridge ( ENB ) told customers.

Force majeure is a provision that allows a contract to be

suspended due to unforeseen events. The receipt point would be

returned to service once the company can replace a

malfunctioning valve, Enbridge ( ENB ) said.