On Thursday Amber offered 9.75 euros ($10.46) per Applus share, beating an offer of 9.50 euros from rival fund Apollo in June and triggering a possible bidding war.

Applus said its board would issue a full report on the offer "in due course" when the Spain's market regulator CNMV authorises the new bid.

The stock market regulator CNMV said on Friday it had to first assess the Apollo bid before processing the offer from Amber.

(Reporting by Joanna Jonczyk-Gwizdala and Matteo Allievi; editing by Inti Landauro and Jason Neely)