Event officials said Charlotte resident Robert Farris caught the record-breaking fish that easily topped the previous state high by more than 100 pounds, WBAL-TV, Baltimore, reported Thursday.
The record blue marlin caught is estimated to be worth nearly $550,000.
The Baltimore Sun said Farris was on board the No Problem out of Fenwick Island, Del., when he caught the marlin.
The White Marlin Open, which is tabbed as the world's largest billfish tournament, has 298 boats registered this year.
Sean Healey of Prides Crossing, Mass., was leading Wednesday in the white marlin category with only two days left in the event. Healey caught a 93.5-pound white marlin estimated to be worth $860,000.