* Staging binding open season
* Shippers to contract for space on Keystone XL
* About 100,000 bpd of capacity available (Adds details)
CALGARY, Alberta, Aug 15 (Reuters) - TransCanada Corp (TRP.TO) said on Monday it will take binding orders until Oct. 17 to ship oil on its Marketlink project, which would link the burgeoning storage hub at Cushing, Oklahoma, to TransCanada's planned Keystone XL pipeline to carry crude to Texas refineries.
The so-called open season gives shippers the opportunity to sign long-term contracts for space on the line to Houston and Port Arthur, if it is built.
The Keystone XL line would carry 510,000 barrels per day of crude from Cushing to Nederland, Texas. However, the open season is only for about 100,000 barrels per day of capacity that hasn't already been contracted to producers in the Canadian oil sands that are looking to ship their oil to the Gulf Coast refining market.
The line has yet to receive U.S. government approvals. A final environmental impact statement for Keystone XL, a key step in the approval process, is expected to be released by the U.S. State Department as soon as this week.
The line has faced stiff opposition from some U.S. environmental groups and legislators, who consider crude from the oil sands of northern Alberta to be more environmentally damaging than conventional oil. They have pressed the State Department to refuse to allow the line's construction
The Marketlink project is one of a handful planned to take oil from the Cushing hub, the pricing point for the New York Mercantile Exchange's benchmark West Texas Intermediate oil contract.
The price of WTI crude has been trading well below the European Brent benchmark, in part because too much oil is flowing into Cushing and there's too little capacity to move it to the Gulf Coast, home to 40 percent of the U.S refining capacity. (Reporting by Scott Haggett; editing by Peter Galloway)