The Bangladeshi government is filing a compensation claim of up to $650m against a US firm for losses following a 1997 gas field explosion.
Bangladesh's energy ministry says the government will file a case with an international arbitration body against the US energy giant Unocal.
The explosion occurred in the now closed Magurchara gas field in the north-eastern Sylhet region.
Unocal insists the claim was settled in a deal in 1998.
Arbitration
However, Energy Minister Mosharraf Hossain, told the BBC that that deal was faulty and the government was reopening the issue.
He said the case would be heard under the rules of the Paris-based International Chamber of Commerce's Court of Arbitration.
A government inquiry estimated the losses at 6.9bn cubic metres of gas.
Mr Hossain said the company had so far only paid $6.3m.