Tesoro Corp. will lay off up to 200 of its 240 employees at its Campbell Industrial Park refinery as it converts the refinery in April to an import, storage and distribution terminal.

Tesoro Corp. said today it will cease refining operations at the Kapolei facility and begin the process of converting it to a storage and distribution terminal.

The company will lay off 190 to 200 of the refinery’s 240 employees, said Jason Kaneao, a Tesoro contract worker with Pacific Consultants and Construction. The company informed employees of the pending layoffs at a meeting at the plant today, said Kaneao, who attended the meeting. 

Tesoro said in an email to the Star-Advertiser, “It is anticipated that approximately 180-200 positions will be impacted.”

Tesoro plans to continue offering the retail assets, which include 31 gas stations with 244 employees, for sale, said Tina Barbee, a Tesoro spokeswoman, in the email.

In a news release the company said: “Tesoro Hawaii will maintain the existing distribution system to support marketing operations and fulfill its supply commitments while continuing to offer the terminal, distribution and retail assets for sale. Upon conversion of the refinery to an import, storage and distribution terminal, Tesoro Hawaii believes third party utilization of the terminal and associated logistics will facilitate ongoing supplies of refined products.”

Officials from Tesoro had scheduled the meeting with employees to announce that  it will no longer refine oil at its facility in Campbell Industrial Park.

San Antonio-based Tesoro put the underperforming refinery up for sale in January 2012, but has not been able to find a buyer. Tesoro met with state officials Monday to brief them of their decision.

The refinery is the state’s largest with a capacity of 94,000 barrels a day. It employs 240 people. The Tesoro news release did not say what would happen to the employees. It also did not say what will happen to Tesoro’s 31 gas stations in Hawaii.

Hawaii has only two oil refineries. The other refinery, operated by Chevron, has a capacity of 54,000 barrels a day.