Postecoglou, 46, had been heavily linked with the vacant Melbourne Victory job in the weeks leading up to Brisbane's grand final triumph.

A National Soccer League championship-winner as a player and coach with South Melbourne, Greek-born Postecoglou is now expected to return to his home town, and take on the challenge of reviving underachieving Victory.

"I would like to express my gratitude to the owners, players and football staff of the Brisbane Roar," Postecoglou said in a statement released on Tuesday.

"Their commitment and belief has created history for this club. I have been very proud to lead such an outstanding group of men, and I wish the club every success in the future."

Brisbane will make an announcement on the now-vacant role of Roar head coach on Wednesday, with Postecoglou's assistant manager, Rado Vidosic, tipped to take over.

"The Brisbane Roar would like to thank Ange for his commitment to the club over the last two-and-a-half years, and the considerable role he has played in its success," Roar director Chris Fong said in a statement.

"We respect how difficult this decision was for him and we wish him well in his new endeavours.

"Ange's departure marks the beginning of a new chapter in the story of the Brisbane Roar, and we are committed to ensuring we have the right people in place to continue the club's legacy with further successes."

Brisbane also released a player statement which read: "As a playing group we would like to voice our appreciation for Ange Postecoglou.

"He has been a huge part of many of us being at the club and helping to drive us to the success we have enjoyed over the past two seasons. We wish Ange every success in the next step of his career.

"While we appreciate all the effort he has put in, we are now focused on the next chapter in the club’s history. As a playing group we are committed to the club, it’s ideals and philosophies and will continue to work hard in pursuit of future success."

Roar came from behind to defeat 10-man Perth Glory 2-1 in controversial circumstances in Sunday's A-League decider at Suncorp Stadium.

Albanian striker Besart Berisha, the league's top scorer this season, went to ground to win a penalty deep into injury time, slotting home the spot kick to win the match for Brisbane in the 97th minute.

It was the Roar's second title triumph in two seasons after they defeated Central Coast Mariners on penalties in last year's grand final.

Postecoglou took over at Brisbane in October 2009, replacing Frank Farina. During his time in charge the Roar embarked on a 36-match unbeaten run, breaking the previous undefeated record for any code of football in Australia.

Brisbane also became the first club to retain their championship crown in the A-League era, under Postecoglou's guidance.