The Delaware court on August 27 affirmed an earlier decision by a lower court relating to a 2005 deal in which Southern Copper bought Minera Mexico from Grupo Mexico (GMEXICOB.MX), which also controlled Southern Copper (SCCO.N).

That court ruled in October 2011 that Southern Copper overpaid by $1.263 billion, and ordered Grupo Mexico to repay the difference to Southern Copper. The court added interest to the damage award, which brought the total to about $2 billion.

Grupo Mexico said it had presented on Tuesday a motion at the Delaware Supreme Court for the case to be reheard.

In the August ruling, the Delaware court also affirmed a controversial $304 million attorneys’ fee approved by the Court of Chancery for the lawyers representing the shareholders who brought the case.

The attorneys’ fee was the largest ever of its kind awarded by Delaware’s Court of Chancery, one of the country’s busiest courts for big shareholder disputes.

Defendants blasted the fee for amounting to $35,000 an hour, more than 30 times the rate in comparable cases.