WASHINGTON, Aug 27 (Reuters) - A U.S. State Department lawyer who played a key role in the Keystone XL pipeline review is moving on, sources said on Wednesday, the latest departure of a senior official involved with the long-delayed project.
Keith Benes helped produce the government's two environmental impact reviews on Keystone, which concluded that the 1,200-mile (1,900-km) pipeline might encourage Canadian oil sands development, but would not meaningfully worsen global climate change.
However, Keystone opponents see the personnel shifts as opportunities to influence one of the most politically charged issues of President Barack Obama's second term.
"This could give us a chance for some fresh conversations," said Anthony Swift, an attorney with the Natural Resources Defense Council, an environmental group opposed to the pipeline.
The oil industry has been cheered by the official findings that Keystone will not seriously worsen global warming and executives have urged quick approval.
Environmentalists, though, say the plan to move 830,000 barrels per day of crude from Canada to U.S. refineries must be rejected as part of a broader campaign to fight climate change.
Benes, a former corporate lawyer, had worked on the Keystone project since 2007 - the year TransCanada Corp sought U.S. permission to build the cross-border link.
Because the pipeline would extend over the U.S.-Canada border, the State Department must either bless or reject the proposal based on its reading of the national interest.
Obama has said he will have the last word on Keystone and that climate change concerns will weigh on his decision.
Benes, who declined comment through a State Department official, fielded industry and environmentalist concerns in the Keystone debate. In September, he will join Columbia University's Center on Global Energy Policy, a think tank led by former Obama energy advisor Jason Bordoff.
Benes' departure is one of several recent instances of senior staff working on Keystone who have left with the project still in limbo.
Carlos Pascual, who led the State Department's energy policy unit, will join Columbia University next month. Kerri-Ann Jones, the department's environmental officer, left government service in April and Genevieve Walker, who oversaw domestic environmental concerns raised by Keystone, left in January.
A department spokesman said the personnel changes "are commonplace and routine" and would not interrupt the Keystone review.
Nebraska landowners have challenged the pipeline route, and the state's Supreme Court is due to hear arguments on Sept. 5.
A ruling in that case is expected late this year. A decision against the pipeline could spur further State Department study, meaning more delays for a project that TransCanada says has cost roughly $2.4 billion so far. (Reporting by Patrick Rucker. Editing by Ros Krasny and Andre Grenon)