Gittens has been one of the top prospects in Europe and has been linked with a move to the Premier League.
The winger had an impressive season that caught the attention of Chelsea, who pushed to sign the forward.
Chelsea want Gittens
After a two-week hiatus, Chelsea and Borussia Dortmund have resumed negotiations for the transfer of Jamie Bynoe-Gittens to the English club, according to Fabrizio Romano, via Sportal.
The Stamford Bridge club has been pursuing the 20-year-old winger for some time, but Dortmund has already rejected two bids of €35 million and €50 million.
The talks are currently taking place in the United States, where both clubs are participating in pre-season friendlies.
Bynoe-Gittens is English and played in Chelsea's academy as a child, before Borussia Dortmund signed him from Manchester City five seasons ago.
Recent reports suggested AC Milan were also interested in the player, but Dortmund denied these claims.