* Syncrude project working with reduced gas supplies
* Imperial Oil and CNRL say gas deliveries resumed
* Suncor restarts operations
By Nia Williams and Scott Haggett
CALGARY, Alberta, Oct 18 (Reuters) - Two of TransCanada Corp's natural gas customers in northern Alberta were without deliveries on Friday, a day after a pipeline break forced some of the biggest producers in the Canadian oil sands to cut back their output.
The rupture in a remote area on TransCanada's 1.6 billion cubic foot per day North Central Corridor pipeline disrupted supplies, which are critical to the operation of projects in the oil sands region. None of the companies affected by the outage were able to give estimates on the overall impact on production.
TransCanada was able to restore service to the region late on Thursday, using a smaller nearby line to reroute shipments around the leaking section of pipe, which was about 140 kilometers (90 miles) west of Fort McMurray, Alberta.
The cause of Thursday's rupture was not yet known, but the three year-old pipeline was safely taken out of service, said Rebecca Taylor, a spokeswoman for the National Energy Board regulator.
TransCanada spokesman Shawn Howard said in an email on Friday that as of late Thursday night the company had resumed natural gas deliveries "to all but two of its northern Alberta customers that were impacted by a line break yesterday."
Syncrude Canada Ltd, one of four producers who reported having to reduce operations because of the outage, still had fewer natural gas supplies on Friday morning.
"We are still working with a reduced natural gas supply to our operation. We are not shipping. We are still continuing to produce and we store on site," said Siren Fisekci, spokeswoman for Canadian Oil Sands Ltd, the largest shareholder in the 350,000 bpd Syncrude project, said.
Imperial Oil Ltd said gas service had resumed at its 80,000 barrel per day Kearl project and Canadian Natural Resources Ltd said supplies had been restored to its 110,000 bpd Horizon and 15,000 bpd Woodenhouse projects.
Suncor Energy Inc said on Friday it had resumed normal operations at it northern Alberta oil sand projects, where production averaged 365,000 barrels per day in September.
Canadian cash crude were mixed on Friday as concerns about reduced crude production eased.
Western Canada Select heavy blend for November delivery was last trading at $29 per barrel below the West Texas Intermediate benchmark, according to Shorcan Energy brokers, compared with a settlement price on Thursday $29.50 per barrel below WTI.
Light synthetic crude from the oil sands for November delivery was last trading at $9.75 per barrel below WTI unchanged from with Thursday's settle.