The 26-year-old product of the club's youth system has made 89 first team appearances for the team and is a regular this season in the starting 11's of coach, Philippe Montanier. He has started all seven of Real Sociedad's matches this season.

Bergara's breakthrough season came last year as he won over Montanier in the closing weeks of the campaign, turning out 11 times as the club struggled successfully to avoid relegation.

The midfielder's contract was due to expire at the end of the current season, but his good form has convinced the club to extend his contract until the end of June 2016.

"I am very happy to be in the club where I have always wanted to play. It is the dream for anyone who has come through the youth system," said Bergara, who insists he can improve as a player.

"I have not hit my ceiling yet and I have the feeling I can give a whole lot more," he continued.

Earlier in the day, Real Sociedad's Basque neighbors, Athletic Club Bilbao announced they had extended the contract of striker Gaizka Toquero for a further three campaigns. Toquero, whose deal also concluded at the end of June 2013, has also agreed a new three year contract and has a buyout clause of 25 million Euros.