Apr. 17--Holly Corp.'s $65 million deal to acquire Sunoco's west Tulsa refinery is part of the buyer's $215 million plan that upgrades the 96-year-old facility to meet stricter environmental standards and could save many jobs, officials said Thursday.

Dallas-based Holly plans to close on the deal June 1, according to reports. Closing is subject to approval of a wide-ranging incentive program by the state Legislature.

The buyers then plan to spend an additional $150 million to install a distillate treating system and sulfur recovery unit over the next two years.

The 400 people now employed at the Sunoco plant are likely to stay on during the transition and upgrades, officials said. Sunoco had planned its own $375 million upgrade but put it off last year due to commodity market conditions, according to reports.

The Tulsa Metro Chamber and the Oklahoma Department of Commerce have worked with Holly officials during the past several weeks on state incentives for the acquisition. Economic development incentives include the Oklahoma Quality Jobs Act and the Investment Tax Credit, according to the chamber.

Chamber officials are asking state legislators to combine the incentive packages in a one-time deal to leverage some of the financing to facilitate the sale.

Philadelphia-based Sunoco Inc. has been looking for a buyer since 2007 and said it would have shifted the plant into a terminal storage operation if it had not found one. A terminal likely would have employed fewer people than an active

refinery.

"This agreement protects about 400 jobs at the refinery," Sunoco spokesman Thomas Golembski said. "We're grateful to the employees at the refinery for their dedication and hard work over the years to make it successful for such a long time."

Holly executives also praised the Tulsa operation's efficiencies. CEO Matt Clifton said the refinery is well known for its transportation diesel fuel, speciality lube oils, and process oils and waxes.

"The talented Tulsa employees and the speciality lubricant products management team who will be joining Holly have done a great job optimizing the capabilities of the facility," Clifton said in a statement announcing the proposed acquisition.

The refinery can process about 90,000 barrels of crude oil a day, according to Energy Department data. An energy analyst, Michael LaMotte of J.P. Morgan, estimated the facility's possible selling price at $500 million in December.

Falling gasoline prices and upgrade factors, however, likely made the refinery impossible to sell at that price.

The plant opened around 1913 and has been part of Sunoco since 1968, according to reports.