Feb. 25 (Bloomberg) -- The Houston Ship Channel, which serves the largest U.S. petroleum port, will reopen to inbound ships at 4 p.m. local time, according to Houston Pilots Organization spokesman T.J. Nelson.

The channel closed last night because of fog, the U.S. Coast Guard said. There are 17 deep-draft ships waiting to head up the 54-mile (87-kilometer) channel to port, including two tankers, Nelson said. Tankers are required to begin and end their journey through the waterway during daylight hours.

``We probably won't get to the tankers today because it takes them about six hours to traverse the ship channel,'' Nelson said.

Fog prompted ship pilots to suspend channel movements overnight along a 360-mile stretch of coast west from Lake Charles, Louisiana, to Corpus Christi, Texas. The area contains 30 percent of U.S. oil-processing capacity, according to data from the plant owners and the National Petrochemical and Refiners Association.

The Galveston-Texas City, Freeport and Aransas-Corpus Christi pilots organizations resumed boarding both inbound and outbound vessels on the ship channels they serve today after suspending vessel movements overnight due to fog.

The Sabine and Calcasieu ship channels remain closed. They serve ports that provide feedstock to refineries representing 11 percent of U.S. oil processing capacity.

Ship pilots guide oil tankers and other vessels through the channels to port. It takes two to three days before a shutdown begins to affect Houston-area refinery operations.

The area has the second-biggest U.S. port of any kind by tonnage and two of the four largest refineries, according to the Greater Houston Partnership.

To contact the reporter on this story: Victor Epstein in New York at vepstein@bloomberg.net.

Last Updated: February 25, 2008 16:00 EST