* Part of Florida Gas Transmission line shut after explosion
* Fifty-five residents evacuated
* Florida gas prices up, in line with other regions
June 18 (Reuters) - A major natural gas pipeline exploded on Tuesday in Washington Parish, Louisiana, destroying a mobile home and causing an evacuation of the area but no injuries were reported, local officials said.
The blast on the Florida Gas Transmission (FGT) pipeline, which transports gas from Texas to south Florida, sent a mushroom cloud into the sky and sparked a fire on the line, according to Lauren Ritchie, a spokeswoman for the Washington Parish sheriff's department.
"There were no injuries and the damage is being assessed," Ritchie said, adding that the fire had been contained.
State and federal officials were taking air quality readings and investigating the incident, which occurred in a rural area near the town of Enon, 80 miles (128 km) north of New Orleans. Ritchie said 55 residents were evacuated.
A section of the pipeline was shut and natural gas rerouted to customers along other parts of the pipeline system, according to a spokeswoman for Energy Transfer Partners, part-owner of FGT.
The spokeswoman did not give a timetable for when the section would restart or have any details on the cause of the explosion. FGT said repairs on the line would begin on Wednesday.
The pipeline has the capacity to carry up to 3.1 billion cubic feet of natural gas per day.
The incident comes as homes and businesses ratchet up their air conditioners to counter warm temperatures in the region, increasing gas consumption. FGT issued an alert on its website, saying it was capping the amount of gas that customers can take from the line due to high demand.
One gas trader said FGT prices were higher on Tuesday, but in line with other next-day prices across the country and likely not due to any effect from the explosion.
Florida prices on the ICE exchange were around $4.12 per million British thermal units, up about 9 cents from Monday. Gas at the nation's benchmark Henry Hub in Louisiana was heard up 12 cents on the day at $3.90.
The explosion caused about 10,000 customers of the Washington-Street Tammany Electric Cooperative in Louisiana to lose power, but a co-op representative said service had been restored to most of them.
The near 5,500-mile Florida Gas Transmission system is owned by Florida Gas Transmission Co LLC, an Energy Transfer Partners-Kinder Morgan Inc affiliate.