* 200,000 bpd Rainbow line shut after spill
* Regulator says leak was significant
* Second Alberta oil line to leak in past week
CALGARY, Alberta, April 29 (Reuters) - A 200,000 barrel per day oil pipeline belonging to a unit of Plains All American Pipeline LP (PAA.N) ruptured on Friday, spilling hundreds of barrels of oil, regulators said.
Plains' Rainbow pipeline, which runs from Zama in northwest Alberta 770 kilometers (480 miles) south to Edmonton, sprung a leak at 7:30 a.m. local time.
"It's not a small leak," said Davis Sheremata, a spokesman for Alberta's Energy Resources Conservation Board, which regulates pipelines in the province. "It's a significant leak, in the hundreds of barrels."
The leak occurred 100 kilometers northeast of Peace River, Alberta, the regulator said.
The ERCB said the line was shut down and the company and authorities were working on cleanup efforts.
The regulator said the spill was 300 meters (985 feet) from and flowing water and 7 kilometers from the nearest residence.
It's the second leak from an Alberta pipeline in a week. Kinder Morgan Energy Partners's KMP.N 300,000 bpd Trans Mountain oil pipeline was shut for five days beginning on April 22 after a small leak was spotted on the line's right-of-way 150 kilometers west of Edmonton. (Reporting by Scott Haggett and Jeffrey Jones in Calgary; editing by David Gregorio editing by Andre Grenon)