The state-owned Port of Wilmington took a step Friday toward a partnership in which Kinder Morgan Energy Partners Inc., a publicly traded energy company, would operate the terminal, expand cargoes, and invest $150 million in needed port infrastructure repairs.

The Diamond State Port Corp. named Kinder, based in Houston with operations at Tioga Marine Terminal in Port Richmond and Fairless Hills, Bucks County, the "preferred" bidder to lease the port.

In coming weeks, Kinder will meet with the port's customers, including Dole and Chiquita, and by the end of March, a "hard"-number proposal should be known, the port's chairman, Alan Levin, told a board meeting in New Castle.

Julius Cephas, president of International Longshoreman's Association Local 1694-1, said the union was concerned about job preservation, salaries, and the potentially hazardous cargoes Kinder might export, such as coal and natural gas. Kinder is one of the largest energy-transport companies in North America, with 75,000 miles of pipelines and 180 terminals.

Cephas said workers and nearby residents were worried about the potential for coal dust, air pollution, spills and gas explosions if Kinder hauls natural gas and coal.

Levin said that although Kinder had not confirmed what cargo it planned to handle, there had been no discussion about storing or shipping coal or petroleum products.

Kinder has given assurances that it will increase the port's business as the largest handler of imported perishable cargo, fruits, and vegetables in the United States, and operator of the largest banana port in North America.

Kinder has not pledged to immediately invest $500 million to build ship berths on the Delaware River, which had been the goal of Gov. Jack Markell's administration when exploring a private partnership in May.

"They have not given us a guarantee they will spend half a billion dollars on the Delaware River, but they will do what is necessary to maximize the value of the port," Levin said.

The board will likely take up the matter again in April, or possibly sooner; Delaware lawmakers will be apprised of the authority's final decision, although it is unclear whether they would vote on it, he said.

The port is now accessible by docks on the Christina River. Expanding on the Delaware would open Wilmington to deeper-bottom vessels.