Petro-Canada restarts Edmonton refinery unit

CALGARY, Alberta, Aug 27 (Reuters) - Petro-Canada PCA.TO has restarted a key processing unit at its Edmonton, Alberta, refinery, but will keep alternative gasoline supply arrangements in place to help relieve shortages, it said on Wednesday.

Petro-Canada said its customers in Alberta and British Columbia -- where as many as 90 gas stations have run out of gas -- would likely see supply improvements by this weekend.

The catalytic cracker unit at the 135,000 barrel a day refinery suffered an unplanned outage on August 3, just as the rest of the plant was to be shut down for 60 days for a major turnaround. (Reporting by Jeffrey Jones; Editing by Scott Anderson)