A U.S. judge ruled that Grupo Mexico SAB must return $1.3 billion in shares to Southern Copper Corp. During April 2005, Southern Copper (previously known as Southern Peru) bought Minera Mexico from Grupo Mexico for $3.75 billion, substantially more than a previous valuation of $3.1 billion. According to Delaware Chancery Court Chief Judge Leo Strine, the transaction was unfair and based on flawed analysis from Goldman Sachs, which served as the financial adviser. The suit was initiated when Southern Copper shareholders sued claiming they had overpaid. Grupo Mexico says it strongly disagrees with the court’s decision and it will file an appeal against the decision with the Delaware Supreme Court.