Shell in December closed operations at the offshore Bonga production platform following a leak from an export line feeding a tanker. The company said preliminary estimates indicated 40,000 barrels of oil spilled, making it one of the worst in Nigeria in decades.
Nigeria's National Oil Spill Detection and Response Agency proposed a $5 billion fine, which represents about $125,000 per barrel spilled, to Nigerian lawmakers. BP, by comparison, could face a $4,300 per barrel penalty for the Deepwater Horizon tragedy.
Shell said the Nigerian penalty was without merit.
"We do not believe there is any basis in law for such a fine," a Shell spokesman was quoted by The Wall Street Journal as saying. "Neither do we believe that Shell Nigeria Exploration and Production Co. has committed any infraction of Nigerian law to warrant such a fine."
Shell said fallout from the spill was minor and the response to the December incident was sufficient.
The response agency needs to justify the proposed penalty to Nigerian lawmakers before it's approved.