ZAGREB (Reuters) - UEFA will decide by the end of this year whether to increase the number of teams competing in the European Championship finals from 2016, delegates at the UEFA Congress were told on Thursday.

The current 16-team format, introduced for the first time in 1996, could be increased to 20 or 24 teams but further studies will continue, said Portugal's Gilberto Madail, who is a member of the UEFA executive committee.

"Any decision to change the competition's format could not be applicable before the 2016 tournament, he said.

Madail said UEFA had studied two formats involving 24 teams, one of which has been dropped, and one option with 20 teams.

"We have had to examine various alternatives that would have to be applied in the qualifying stage," he said, adding that changes to the finals would not have a significant bearing on the qualifying competition.

HIGH-LEVEL MATCHES

One format considered for a 24-team tournament involves six groups of four teams, last used at the 1994 World Cup finals in the United States.

The top two from each group and the four best third-placed teams would progress to the knockout stages.

A 20-team format would have four groups of five teams with the top two in each group advancing.

"For quality reasons, the finals with 16 teams is the best because it brings high-level matches," said Madail.

"But a final phase with 20 or 24 teams provides added value because it has the advantage of providing more fans. An option of 20 teams would be a viable compromise."

"But we would need more accommodation and more security, meaning that we would have to reduce the number of potential host countries."

The championship currently lasts approximately three weeks and comprises 31 matches.

An expansion to 20 or 24 teams would mean about 20 extra matches being played, depending on the format chosen.

UEFA's 53 member associations will have the chance to comment on the proposals before a decision is taken.

Euro 2008 is being co-hosted by Austria and Switzerland in June, while Poland and Ukraine will stage the finals in 2012. Bidding has not yet begun for the 2016 finals.

(additional reporting by Zoran Milosavljevic)

(Reporting by Mike Collett, Editing by Ken Ferris)