(Adds more information on US World Cup history)

By Aditya Soni and Jaspreet Singh

July 21 (Reuters) - Nearly 63 million Americans tuned in to watch Spain beat Argentina in the FIFA World Cup final on Sunday, shattering viewership records and underscoring soccer's growing appeal in the U.S. after decades of efforts to broaden its audience. Held in New Jersey, the final remained scoreless until Spain broke through in the 106th minute to secure a 1-0 victory.

Fox's English-language broadcast attracted 38.9 million viewers, while Comcast's ( CMCSA ) Telemundo and its Peacock streaming platform pulled in another 23.9 million viewers for the Spanish-language coverage, the companies said. The combined audience far exceeded the 22.3 million U.S. viewers who watched the 2022 World Cup final in Qatar.

The strong viewership capped what analysts said was a solid run for the tournament's broadcasters, with Fox and Comcast ( CMCSA ) paying roughly $485 million and $600 million, respectively, for rights packages that included the World Cup, according to media reports. Several knockout-stage matches also outperformed recent championship games in other major U.S. sports. The Round of 16 meeting between England and Mexico drew nearly 45 million viewers, well above the roughly 27 million who watched Game 7 of Major League Baseball's World Series, when the Los Angeles Dodgers beat the Toronto Blue Jays in extra innings, and the nearly 25 million who tuned in for Game 5 of the NBA Finals, where the New York Knicks ended a 53-year title drought by defeating the San Antonio Spurs. While the figures remained below the nearly 126 million viewers who watched Super Bowl LX, when the Seattle Seahawks defeated the New England Patriots, they marked a significant milestone for a sport long overshadowed in the U.S. by American football, basketball and baseball. The tournament, co-hosted by the U.S., Canada and Mexico for the first time, benefited from prime-time kickoff slots for American audiences. Fans were also drawn by what could be the final World Cup appearances of a generation's biggest stars, including Argentina's Lionel Messi and his long-time Portuguese rival Cristiano Ronaldo. The last time the U.S. hosted the tournament was in 1994. Fox One, which had the English-language streaming rights in the U.S., recorded 2.8 million sign-ups in June, its strongest month since the service's launch in August and more than double the 1.1 million sign-ups generated during NFL Playoffs in January, according to industry tracker Antenna.

Soccer's popularity among Hispanic audiences also drove strong turnout on Spanish-language broadcaster Telemundo.

"Ratings have blown past internal forecasts for both networks, and it's not close," said Vicente Navarro, managing partner at soccer-focused marketing firm GotDigital. Navarro said a marquee 30-second advertising spot in the knockout-stage matches cost as much as $1 million, more than double 2018 levels. Major advertisers included PepsiCo ( PEP ), Home Depot ( HD ), Anheuser-Busch and Coca-Cola, according to market intelligence firm SensorTower.

For comparison, a 30-second Super Bowl advertisement typically costs about $8 million or more.

WATER BREAKS PROVE LUCRATIVE FOR FOX Beyond the ratings, the tournament also proved lucrative for broadcasters, helped by new so-called hydration breaks that split matches into four segments and created additional advertising opportunities. Some experts said the extra ad slots helped offset TV rights costs and drew interest from beverage and food brands. Fox, led by Lachlan Murdoch, is expected to make at least $250 million from hydration-break advertising alone, according to a June report by the Hollywood Reporter. Telemundo did not run ads during those breaks.

"The new inventory definitely creates more spending for the World Cup," said Luke Stillman, a managing director at research firm Madison and Wall. "It would be surprising if the structure wasn't a permanent fixture now going forward, and therefore the broadcast rights are going to be more valuable going forward." Still, it remains unclear whether some of the tournament's Americanized elements, including a major halftime show that drew comparisons with the Super Bowl and led to a 27-minute interval, well beyond soccer's sacrosanct 15-minute halftime period, will endure. FIFA also announced the World Cup champions will for the first time receive a ring in a nod to "one of the most recognisable American sporting traditions."

The next World Cup will be co-hosted by Spain, Portugal and Morocco in 2030, followed by Saudi Arabia in 2034. Both tournaments are likely to feature less favorable kickoff times for U.S. viewers, which could weigh on future ratings.