(Reuters) - A record $1.39 billion will be legally wagered in the United States on Sunday's Super Bowl match-up between the two-times defending champion Kansas City Chiefs and Philadelphia Eagles, the American Gaming Association said on Tuesday.

In years past, the trade group representing the U.S. casino industry did not break out an estimate solely for legal bets but rather one for all wagers, including those placed online, with a sportsbook, unlicensed bookmaker or casually with friends.

But with years of legal operations in several U.S. states, the AGA said it now analyzes historical revenue data and other trends to develop a legal wager estimate for major U.S. sports betting moments.

The AGA's estimate for Super Bowl bets in up 11.2% from the $1.25 billion that gambling and research firm Eilers & Krejcik predicted would be legally bet on last year's NFL championship in Las Vegas between the Chiefs and San Francisco 49ers.

"No single event unites sports fans like the Super Bowl, and that excitement extends to sports betting, with this year's record legal handle reflecting its widespread appeal," AGA President and CEO Bill Miller said in a news release.

"This figure underscores the positive impact of the legal market-from protecting consumers to generating tax revenue that benefits communities across the country-while enhancing the game experience for all."

In 2018, the U.S. Supreme Court struck down federal ban on sports betting. Since the ruling, 38 states and the District of Columbia have now legalized sports betting in some form.

The NFL's championship game creates an annual betting bonanza and this year's edition will be played in New Orleans for a record-tying 11th time.

The Chiefs, appearing in the Super Bowl for the fifth time in six years and seeking an unprecedented third consecutive NFL championship, are slight favourites to beat the Eagles in a rematch of the February 2023 title clash.