Extra officials will be behind each goal-line for Champions League matches and Euro 2012 qualifiers for the next two seasons, UEFA announced on Thursday.
The 'five officials' experiment follows the trial in the Europa League using the same system which has been proposed by UEFA president Michel Platini as an alternative to technology. The International FA Board, the game's rule-making body, last week gave the green light to two more seasons of experiments and UEFA's executive committee decided to implement the trials in their showcase competitions.
"The two additional referees will give more flow to the game," said Platini. "The arrival of TV has shown up referees' mistakes - the referee sees a lot but with an extra four eyes you will see more things and you help the referee to take a better decision."
He added: "My problem as the originator of this idea and UEFA president and FIFA vice-president is that we have to cover all the parts of the field.
"That's why I have been fighting for this. TV cameras show all the mistakes in slow motion."
The FA, Premier League and Football League have said they are unlikely to experiment with the extra officials in any of their competitions.