Chelsea have signed Romeo Lavia on a seven-year contract from Southampton it was announced Friday in the latest addition to their squad after the teenage midfielder rejected a move to Premier League rivals Liverpool.

No fee has been disclosed but British media reports estimated the worth of the deal at £53 million ($67.5 million, 62 million euros), possibly rising to £58 million.

Lavia, 19, is the eighth player to join Chelsea in the current transfer window, with the London club, now owned by a consortium led by American businessman Todd Boehly, having spent more than £350 million -- although they have sold several high-value footballers as well.

Belgium international Lavia has made 29 Premier League appearances and has arrived at Stamford Bridge following south coast side Southampton's relegation from English football's top-flight last season.

"I can't wait to meet all my new team-mates and build a chemistry together to achieve great things together," Lavia told Chelsea's website.

He is now set to compete for a place in Chelsea's midfield with Enzo Fernandez and Moises Caicedo -- the two most expensive players in English football transfer history.

Caicedo arrived from Brighton earlier this month for a reported fee of up to £115 million, surpassing the £107 million the Blues paid Portuguese giants Benfica for Fernandez back in January.