UK-based buyout firm Apax Partners has emerged as the favourite to win a four-horse race to acquire Spanish bus company Avanza for €600m ($770m), after final round bids were submitted last night.

Deal sources said Apax had partnered with UK bus operator National Express, which owns Spanish market leader Alsa and was the frontrunner to win the Avanza auction. Sources said four bids including Apax's had been made in yesterday's final round.