ALLENTOWN, Pa. -

PPL announced Thursday plans to build a new 725-mile regional transmission line that will run through four states.

According to PPL, the new line would make electric service more reliable, reduce the cost of electricity to customers while enhancing the security of the electric grid.

According to preliminary estimates, the cost of the project would be between $4 billion and $6 billion.

PPL Electric Utilities submitted the project to PJM Interconnection to start the competitve bidding process.

The proposed 500-kilovolt line would run from western Pennsylvania, into New York and New Jersey, and south into Maryland.

The project is in the preliminary planning stages, officials said.

If approved and built as proposed, the line would help replace supplies of electricty that will be lost when existing power plants retire, PPL officials said.

The new line would also help prevent power shortages during periods of extremely high demand, as in the prolonged severe cold weather this past winter.

PPL has begun to determine the best route and final details of the proposed line.

The company will have an inclusive public outreach process and would consider public input when making a final route selection.

PPL Electric Utilities will be meeting with appropriate state and federal agencies as planning for the project moves forward.

Assuming all necessary approvals are received, and construction starts in 2017, the project is estimated to finish between 2023-2025.