Sen. Bob Casey Jr. (D., Pa.) and the Delaware County Council on Wednesday urged ConocoPhillips to sell its refinery in Trainer to a buyer that would keep the refinery operating as a manufacturing facility rather than as a fuel storage terminal.

Prompted by rumors that potential buyers of the ConocoPhillips refinery in Trainer plan to shut down the plant, the elected leaders wrote Wednesday to ConoccoPhillips chief executive James Mulva to urge him to sell the plant to buyer that would operate it as a refinery, which would employ more people and require more investment than a fuel-storage facility.

Delta Air Lines is reportedly a top bidder to buy the refinery. ConocoPhillips declined to comment on sales process. "ConocoPhillips is making every effort possible to find a buyer for the refinery and we are planning for the sales process to continue through the end of May," spokesman Rich Johnson said in an e-mail.

— Andrew Maykuth