* Gas leak shuts Oseberg A platform, under control in hour
* Oseberg field output 54,200 boed in Q3 -Statoil
* Oseberg B and Oseberg D platforms also down after leak
* Oseberg C platform online along with satellite fields
* Production to remain down for unknown period (Adds restart timing for Oseberg platforms)
By Walter Gibbs
OSLO, Jan 24 Oil production at Statoil's (STL.OL) Oseberg A, B and D platforms in the North Sea was shut down on Monday after a gas leak and will remain closed for a "few days," the Norwegian oil company said.
Statoil spokesman Ola Anders Skauby said that the leak was controlled within an hour of the 0740 GMT incident and that production from the affected areas, which include the Oseberg South and Oseberg East fields, would stay shut "for a few days."
He said Oseberg platform C was still producing along with its satellite fields: Huldra, Veslefrikk and Brage.
The output of the Oseberg field as a whole was 54,200 barrels of oil equivalent per day in the third quarter, Statoil said. It was not clear how much production was lost on Monday.
Skauby said the leak was discovered during work on a pipe. No injuries were reported but most of the platform's 303 workers mustered into lifeboats, which were not launched.
"A controlled shutdown was initiated, and then to more quickly ease the pressure on the system they initiated the emergency shutdown procedure, which causes the general alarm to go off," he said.
Asked if there had been an explosion danger, Skauby said: "The platform management felt they had control over the situation during the whole incident." (Editing by William Hardy, editing by Gerald E. McCormick)