bp said on Friday its 435,000 barrel-per-day (bpd) Whiting, Indiana, refinery is returning to normal operation after boilers and electrical utilities were restored.
An Aug. 24 fire on a single electrical system forced the shutdown of the entire Chicago-area refinery.
"We are continuing to work around the clock to bring the plant back to normal operations," said bp spokesperson Christina Audisho in an emailed statement.
BP plans to restore at least partial production of motor fuels by Sunday, according to sources familiar with plant operations.
BP began restarting the refinery on Wednesday. The first units brought on-line were the crude distillation units (CDUs), which break down crude oil into feedstocks for all other units, according to the sources.
Next the company is restarting fuel production units including at least one of the gasoline-producing fluidic catalytic crackers (FCCs), the sources said.
Chicago motor fuels prices have leveled out since jumping last week on news of the shutdown of the largest refinery in the U.S. Midwest.
Chicago CBOB gasoline was little changed at 19 cents a gallon above futures on Thursday, traders said. Chicago ultra-low sulfur diesel gained half a cent, trading 28 cents a gallon above diesel futures on Thursday.