By David Sheppard
NEW YORK (Reuters) - Exxon Mobil Corp <XOM.N> was granted time by regulators to carry out a second round of testing on the ruptured Pegasus oil pipeline, after the firm said an initial investigation into the reason the nearly 70-year-old line failed was not conclusive.
The 95,000-barrel-per-day (bpd) line has been shut since spilling thousands of barrels of heavy Canadian crude oil into the town of Mayflower, Arkansas, in late March, and questions have been raised over whether it will ever be restarted.
State politicians have asked Exxon to relocate a 13.5-mile section of the line away from Little Rock's drinking supply as safety concerns about transporting Canada's tar sands on ageing U.S. infrastructure have mounted.
U.S. Department of Transportation's Pipeline and Hazardous Materials Safety Administration (PHMSA) has granted Exxon until July 10 for further testing of the failed pipe as long as the companies provides "information regarding the additional testing and protocols."
In May, the first independent report into Pegasus's failure was sent to Exxon and PHMSA by a third-party laboratory.
Exxon has said the Hurst Metallurgical Research Laboratory needs more time for additional testing of the 52-foot section of the damaged pipeline.
"On review of the draft report, EMPCo (Exxon Mobil Pipeline Company) believes additional mechanical and metallurgical testing is warranted to better understand the pipe properties and potential failure mechanisms," EMPCo said in a letter to PHMSA dated June 6.
Pegasus normally carries heavy Canadian crude from Patoka, Illinois, to Nederland, Texas. With the shutdown of the line, large volumes of crude oil have been diverted into Cushing, Oklahoma, the delivery point of the U.S. crude oil contract.
PHMSA declined to comment on the extension, beyond its public response to Exxon on June 6.
A spokesman for Exxon said the firm would "continue to work cooperatively with the agency on any follow-up actions."
Exxon said in late May it would not decide on the line's future until the investigation was completed.
(Additional reporting by Timothy Gardner in Washington; Editing by Jeffrey Benkoe and Gunna Dickson)