HOUSTON (Reuters) - BP Plc plans to cut between 50 and 80 salaried positions at the company's 413,500-barrel-per-day refinery in Whiting, Indiana, a company spokesman said on Wednesday.

Union-represented hourly and salaried employees at the refinery, which is BP's largest in the United States, will not be affected by the layoffs, said spokesman Michael Abendhoff.

The cuts come as U.S. refiners have weathered a sharp downturn in refining profits due to rising global oil prices.

"We are always looking at our business to make sure that we have the right people in the right roles to operate efficiently, safely and reliably," Abendhoff said.

Abendhoff did not say when the cuts, which are between 3 percent and 4 percent of the plant's total workforce of 1,800 employees and contractors, would take effect.

(Reporting by Erwin Seba; Editing by Lisa Von Ahn)