Alexander Rossi has parted company with the Caterham Formula 1 and GP2 teams, the American announced on Wednesday.
Rossi joined Caterham in 2011 and has raced for the Leafield-based operation since then both in Formula Renault 3.5 and in GP2, where he was competing this year.
Caterham announced new owners at the start of the month, with Tony Fernandes selling the outfit to a group of Swiss and Middle East investors.
Rossi joined Caterham as F1 reserve driver for 2013, and has driven in Friday practice sessions and in tests since then, also competing in the GP2 series.
The 22-year-old said he will not be racing for the GP2 squad in Germany this weekend.
"I'm very thankful to everyone at Caterham throughout the time I have worked with the team," he said. "We had meetings over the past couple months with the previous and new management.
"The decision we took to leave Caterham is the right decision for my career.
"I take with me only the positives from my time there, where I logged considerable F1 mileage, driving each of their F1 cars since Lotus Racing entered the F1 World Championship in 2010. I have proven my abilities in F1 equipment, in both testing and free practice sessions, and I'm ready for the next step."
Rossi says he remains focused on securing a racing drive in Formula 1.
"My goal is to be in F1 and add value to the sport," Rossi added.
"We have a great opportunity to grow the sport in the States and I believe the timing is perfect. I'm also very pleased to see an American F1 entry, Haas Formula with plans to join the F1 grid in 2016."