The Australian has two years remaining on his existing deal with the British team but said that the presence of Chris Froome at Team Sky means that he is likely to go elsewhere in 2016. Porte signed a two-year contract extension in May of this year, meaning that his current deal does not expire until the end of the 2015 season.
"As much as I love being there and being the wingman, it's not what I always want to do," Porte told The Herald Sun before travelling to Europe for the team's training camp in Mallorca.
"I've shown by winning Paris-Nice and coming second in the Dauphiné and Basque, they're pretty big races in the sport. I think the next move for me is two more years at Sky, but then I really think I need to get out and ride in a team where I'll be the leader."
Porte joined Team Sky from Saxo Bank at the beginning of 2012, and played an important part in helping Bradley Wiggins and Chris Froome win the past two Tours de France. The 28-year-old was handed the reins of leadership for Paris-Nice in 2013, where he claimed overall honours, and at the Tour of the Basque Country, where he finished second behind Nairo Quintana (Movistar).
For most of 2013 Porte was relegated to a role in support of Froome, finishing second behind his teammate at Critérium International and the Critérium du Dauphiné. However, Porte said that Froome’s status as Team Sky's leader is not open to debate, particularly given that he races under a British licence. Like Porte, Froome will turn 29 next year.
"I think Chris Froome is the rider of this generation. I think he's going to win more than one Tour and it's unrealistic of me, in a British team, when he's got a British passport [to assume control]," Porte said. "To be honest, it's going to be hard to beat Chris, but in another team who knows?"
"Me personally, I think I do have the qualities to be a contender. I mean, I can climb and time trial and hold my own in the descents too. The ultimate GC rider has to be good at everything."
Although Porte suffered a jours sans on the 2013 Tour’s second mountain stage to Bagnères-de-Bigorre, he took heart from his strong showings in support of Froome elsewhere during the race and he admitted to wondering what he could have achieved had he not been riding as a deluxe domestique.
"I was there in situations where it was Froome, [Alberto] Contador and Porte and I was thinking, 'Well, I need to start being a little bit more selfish next year and ride for myself'," said Porte, who will lead Sky at the Giro d’Italia next season before teaming up with Froome at the Tour.
"I'll have the opportunity to ride in the Giro and ride for myself. For me, the dream is to win a Grand Tour, any Grand Tour. I've been out of Australia long enough to realise there are other races other than the Tour."