The Auto GP season has been suspended due to a low number of entries ahead of the planned visit to Paul Ricard this weekend.
The single-seater series had a field of nine cars at the opening round at the Hungaroring, but this shrunk to seven for the races at Silverstone a month ago.
Ex-Formula 1 racer Antonio Pizzonia led Facu Regalia in the standings after two wins from the first four races.
A statement from the series organisers said that the 2015 season will be resumed if it attracts an 'adequate' number of entries.
"The organisation wants to underline that the 2015 edition must not be considered over," it said.
"Following to an accurate revision of its strategy, Auto GP is aiming to be back on-track soon, provided that the level is appropriate to its heritage.
"As soon as there will be an adequate number of participants, the championship will be restarted with the necessary modifications to the original calendar."
Rounds at Zandvoort (supporting the DTM), Brno and Barcelona were due to follow Paul Ricard on the schedule. A season opener supporting the World Touring Car Championship in Marrakech had previously been cancelled.