A New York Court Judge this week ruled that Universal Music owner Vivendi must pay £629m (€765m/$999m) to Liberty Media Corporation, plus interest dating back to 2001.
The case dates back to Vivendi’s acquisition of Liberty Media’s stake in USA Networks Inc in 2001.
The French company, which also owns video games maker Activision Blizzard, has announced its intention to appeal.
It said in a statement to Music Week: "Vivendi strongly believes that it did no wrong and intends to pursue its appeal to the fullest extent possible."
The New York judge's verdict compounds a jury awarding the sum (minus interest) in damages to Liberty Media last July.
Liberty Media claimed in its original 2003 lawsuit that Vivendi had waited until its transaction with USA Networks officially closed before publicly acknowledging a downgrade of its debt rating and addressing concerns about liquidity.
The New York Court this week awarded prejudgment interest at the low rate of a one-year US Treasury Department bill, as requested by Vivendi.
Liberty Media sought judgment in Euros converted to dollars plus interest of 9% a year,