Major League Soccer will announce a new team in San Diego on Thursday after British-Egyptian billionaire Mohamed Mansour paid a record expansion fee of around $500 million, a person with knowledge of the plans has told AFP.

The 30th club in MLS will play at the recently built 35,000 capacity Snapdragon Stadium, home to the San Diego Aztecs college football team and the San Diego Wave, the National Womens Soccer League franchise.

The previous record fee paid for entering MLS was the $325 million committed by Charlotte FC in 2019. The original entry fee to MLS, for its first season in 1996, was $5 million.

The value of MLS teams has increased significantly in recent years. When Orlando City joined the league in 2015 their owners paid $70 million while Los Angeles FC's owners forked out $110 million five years ago.

The new San Diego team, whose name has yet to be revealed, is earmarked to start play in the league 2025 and will be the fourth MLS team in California along with the San Jose Earthquakes, Los Angeles Galaxy and Los Angeles Football Club.

The source said the new club will not have any link to the current San Diego Loyal who play in the second tier USL Championship.

The Loyal, who count former MLS and United States national team star Landon Donovan, among their ownership group, have said they will continue despite the impending new arrival.

"Our plan is simple. We aren't going anywhere," said chairman and owner Andrew Vassiliadis in a statement.

"Landon Donovan, the entire San Diego Loyal team and I are dedicated to this mission, and we will continue to work tirelessly to achieve it. Our passion for soccer and for our community will never falter," he added.

MLS Commissioner Don Garber, who said in March he was "bullish" on San Diego's chances of becoming the 30th team has indicated the league could be looking for two more markets in the coming years.

Las Vegas, Sacramento, Detroit, Phoenix and Tampa have all been mentioned as possible future locations for MLS clubs.

While 32 teams is much bigger than most first division leagues around the world, MLS, with teams from the United States and Canada, operates with an Eastern and Western Conference.

The NFL and NHL both have 32 teams while the NBA and Major League Baseball both have 30 teams each.

Mansour's ownership group also includes the Sycuan Band of the Kumeyaay Nation, a federally recognised Native-American tribe located in the San Diego area.

The 75-year-old Egyptian born Mansour is a British citizen and lives in London

He is chairman of his family's Mansour Group which is involved in the automotive industry, financial services and real estate. Mansour also serves the senior treasurer of Britain's Conservative Party.

The San Diego investment comes ahead of an expected boom in interest in the sport in the United States which is co-hosting the 2026 World Cup along with Mexico and Canada.

This season MLS launched a new global broadcasting deal with Apple TV worth a reported $2.5 billion over ten years.

San Diego's NWSL team has the two highest attendance's in league history for an individual game.

The record was set at Snapdragon Stadium in September last year when 32,000 saw the Wave beat Angel City FC.