Florida Power & Light Co. filed a proposal with state regulators Tuesday to build a $1.5 billion 300-mile natural gas pipeline in eastern Florida.

The pipeline, dubbed the Florida EnergySecure Line, would extend from Palm Beach County in South Florida to Bradford County in the northern part of the state. The pipeline could enter service as early as 2014, Florida Power & Light said.

Florida Power & Light is the utility subsidiary of FPL Group (FPL), Juno Beach, Fla.

The utility reviewed a number of options for meeting gas demand in Florida, but determined that the proposed pipeline "was the most cost-effective approach for our customers," said Randy Clerihue, a spokesman for Florida Power & Light.

The Florida EnergySecure Line would be the third major natural gas pipeline in the state. Natural gas supplies to the other two, the Florida Gas Transmission Co. and Gulfstream Natural Gas pipeline systems, were increased significantly in 2008 with the construction of the Southeast Supply Header pipeline.

That pipeline, a joint venture between Spectra Energy Corp. (SE) and Centerpoint Energy Inc. (CNP), extends 270 miles from the Perryville Hub in northern Louisiana to interconnections with the two Florida pipelines in southern Alabama.

About two-thirds of the planned pipeline's capacity would be used to fuel power plants in Cape Canaveral and Riviera Beach that are being upgraded to run on natural gas instead of fuel oil.

Since the pipeline wouldn't enter service until 2014, customers wouldn't see increases in their bills related to the pipeline before that time, Clerihue said.

The Florida EnergySecure line would use existing rights of way associated with utilities, roads or railroads for about 90% of its length, Florida Power & Light said.

Florida Power & Light, the largest electric utility in Florida, serves 4.5 million customer accounts in the state.

-By Christine Buurma, Dow Jones Newswires; 201-938-2061; christine.buurma@dowjones.com