The Philadelphia Regional Port Authority will seek "expressions of interest" to develop the 200 acres known as Southport, at the eastern end of the Navy Yard in South Philadelphia.

The board agreed at its monthly meeting Tuesday to accept proposals - called "request for expressions of interest" - from terminal operators, steamship lines, automobile manufacturers, energy companies, and investment firms with ideas for the maritime property, south of the Walt Whitman Bridge on the Delaware.

The PRPA will then evaluate the submissions - the deadline is Nov. 14 - and may ask for financial and business plans. The process could take several months.

Among those interested is Philadelphia Energy Solutions, which operates the former Sunoco Inc. refinery. Chief executive officer Philip L. Rinaldi spoke to the PRPA board Tuesday. He did not provide specifics, but said an energy port would have a "huge wharf" to handle large oil tankers.

He said all 200 acres may not be needed. "I certainly believe there will be plenty of room left for other things for the port," Rinaldi said. "You've got an opportunity to have energy underwriting a lot of the cost of development of that site on which other things could piggyback."

The Philadelphia refinery is close by Southport and would be "easily connectable by pipeline," Rinaldi said.

Manufacturing would likely remain at the refinery. The energy port would move crude in, and export products out. Currently, crude comes into the Fort Mifflin Terminal Complex owned by Sunoco Logistics at Hog Island near the Philadelphia airport. A new facility could mean the ships would come to Southport.

Boise Butler, president of International Longshoremen's Association (ILA) Local 1291 and a PRPA board member, wanted to hear more about how an energy port could "coexist" with a traditional container-cargo shipping facility.

"We have constraints on the river. We don't have any more room for containers at Packer Avenue," Butler said. "The only room left is south of the Walt Whitman Bridge."

When the Panama Canal expansion is completed next year, and cargoes come from Asia to the East Coast, "it won't make a bit of difference if the last 200 acres of land - the last frontier for growth - becomes an energy port," Butler said.

"Are we going to send the business to New Jersey? Did we do all this dredging" to deepen the Delaware navigation channel from 40 feet to 45 feet "only to send the cargo elsewhere?" he asked.

James Paylor Jr., vice president of the ILA executive council, said container volumes were up 29 percent in the Philadelphia port. "We cannot stevedore a vessel on Broad Street," Paylor said. "Is there a way to address the compatibility of the two industries [energy and container shipping] to see what footprint comes out?"

Among those interested in Southport is marine terminal operator John Brown Jr., who runs a paper-import business from Piers 38 and 40 and 78 and 80 in South Philadelphia. Brown said in an interview that he would submit a proposal and was "very close" to having a partner.

Brown recently hired Vincent J. Fumo, the former state senator and a longtime family friend, to advise him after Brown said he learned that a terminal competitor, the Holt family, may have talked with Rinaldi about teaming up to run Southport - without a public bid process.

Rinaldi said Tuesday that his company "was not looking for a private deal. That's not how we operate. I talk with everybody."

Leo and Tom Holt Jr., whose family owns Gloucester Terminals L.L.C. in Gloucester City and runs Packer Avenue Marine Terminal in South Philadelphia, have not decided whether they will submit a development proposal for Southport, said spokesman Kevin Feeley.

The PRPA, a state agency that owns land and piers on the Philadelphia side of the river, voted June 17 to engage in a "public process" for Southport after a group that won the bid in 2010 to develop the property bowed out in April.

"The ideal development for Southport would be a combination energy port and marine terminal," said Charles Kopp, PRPA board chairman. "The energy port is the enlightened vision for the future of Southport, and the marine terminal carries forward the long tradition of port operations in Philadelphia."