HOUSTON, Sept 3 (Reuters) - Two of Louisiana's largest refineries began efforts to make gasoline and other fuels on Friday when power was restored five days after Hurricane Ida knocked out much of the state's oil processing.

Marathon Petroleum Corp on Friday said its 578,000 barrel-per-day (bpd) Garyville, Louisiana, refinery, the state's largest, was in the initial stages of restarting.

It followed Exxon Mobil Corp's resumption of operations at its 520,000-bpd Baton Rouge refinery. The U.S. Department of Energy offered Exxon and Placid Refining Company a combined 1.8 million barrels of crude oil from the U.S. Strategic Petroleum Reserve (SPR) to replenish stocks.

Entergy Corp restored power to about a quarter of affected customers, it said on Friday, laying out a schedule to provide power to major Louisiana cities by Tuesday.

In all, nine refineries were knocked offline by Ida's winds and utility power losses. Five could be back online by within two weeks, estimated Robert Campbell, head of oil products research at consultancy Energy Aspects.

But obtaining supplies from U.S. offshore producers may take longer, he said.

"Refiners might resort to the SPR to request crude as Exxon did if pipelines from the Gulf are not ready by then," said Campbell. "They could also import crude, which would take time."

PBF Energy on Friday said it was receiving limited power at its 190,000-bpd Chalmette refinery but could not predict when operations could fully resume. A restart could begin over the weekend, people familiar with the matter said.

Power was returning to Valero Energy Corp’s 215,000 bpd St. Charles refinery in Norco, GasBuddy.com analyst Patrick De Haan said.

Valero did not reply to a request for comment.

Placid Refining's 75,000-bpd Port Allen refinery and Delek US Holdings' 80,000-bpd plant in Krotz Springs, could also see power restored soon under Entergy's plan.

Neither Placid nor Delek replied to requests for comment on Friday.

Phillips 66's Alliance refinery on the Louisiana coast was still being evaluated for damages. Any restart would depend on those assessments and the availability of electricity, it said. (Reporting by Erwin Seba and Marianna Parraga; Editing by Marguerita Choy and Grant McCool)