"Australia, the moment has arrived to say 'arrivederci'," Del Piero said in statement on social media.

"My adventure with Sydney FC is about to be concluded, and, even if it makes me rather sad, because I have had a wonderful time here, I have communicated my decision to the club.

"I'm really grateful for the last two years and for the club's request for me to remain and with whom, I am happy to explore new opportunities to continue our relationship."

The two parties had been in discussions for months about extending Del Piero's two-season stay in Australia, but Sydney FC chairman Scott Barlow said the 39-year-old player had decided to end his time with the team.

"While it would have been fantastic to see Alessandro remain in Sky Blue, ultimately this has been his decision," Barlow said.

"Two years ago Sydney FC signed one of the greatest players to have ever worn a football shirt."

The former Juventus great, the biggest signing in Australia's domestic league history, has played a major role in increasing attendance, television audiences and media interest in the domestic A-League.

"It hasn't been an easy choice, also because my life on and off the pitch has been fantastic, my family and I have really enjoyed these two wonderful years: Australia will remain in our hearts forever," Del Piero said.

Barlow said Del Piero had "laid the foundations for a lasting legacy and he has inspired a whole new generation of Sydney FC football fans and future players."

Sydney FC said there would be discussions with Del Piero about continuing his relationship with the club.

"Today is bitter-sweet. While we would have liked to see Alessandro remain at Sydney, his decision now allows us to further our discussions about some exciting new opportunities for our ongoing relationship and to build on the legacy that has been started," Barlow said.

"It has been a pleasure and a privilege to have him at our club and we look forward to seeing him in the near future when he is next back in Sydney."

The Italian great spent 19 years at Juventus, scoring 208 goals in 513 appearances before joining the A-League.

Del Piero said he would continue to be close to Australian football and the Australian Football Federation (FFA), who has employed him as an ambassador of the 2015 AFC Asian Cup in Australia.

"The moment has arrived to make some changes. I am well aware that I have given a lot and received even more," he said.

"Now I just need some time to think over all the prospective opportunities for my future."