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A Texas jury has hit JP Morgan Chase for more than $4 billion in damages for mishandling the estate of a former information technology executive who pioneered American Airlines' SABRE reservation system.

A Dallas County Probate Court jury sided with widow Jo Hopper and her two stepchildren Tuesday after a four-week trial. The jurors found the bank breached its fiduciary duties and contract by failing to properly handle the $19 million estate of Max Hopper, according to a verdict sheet and press release from Loewinsohn Flegle Deary Simon LLP, which represented Jo Hopper.

Max Hopper died from a stroke without a signed will in January 2010, according to the law firm. Under state law, the couple's assets acquired during their 28-year marriage were divided between Jo Hopper and his two children from a previous marriage, Stephen Hopper and Laura Wassmer.