The Welshman had reportedly already signed a renewal deal that the lawyers were looking over ahead of the 2018 Tour de France, but could switch teams given his remarks to the BBC.
"For sure, you want to listen to what people have to say because there are a lot of other strong teams around, it's not just like Sky is up here and everyone is down there," Thomas said. "You just need to sit down properly, look at the positives and negatives and go from there."
Thomas joined the when Sky debuted in the WorldTour in 2010. He went from being a track/Classics rider to Grand Tour contender. After several unlucky episodes, he pulled off a Tour win in Paris in July.
The super team have already locked in Chris Froome last summer through the 2020 season. They have not announced any such deal with 32-year-old Thomas yet.
"It's quite fortunate I didn't sign before the Tour! The team worked for me, we won the Tour, it's crazy, but the way team is run works really well for me. But I'm open to hearing other options," Thomas said.
"I don't just want to go to any ol' team because the main reason I won the Tour is because the strength of the team in this race. If you have the legs, the percentage of winning improves if you have the team around you. But, yes, it's interesting times."
Team Sky may have a hard time keeping Thomas with Froome on their books and emerging Colombian star Egan Bernal. If Thomas stayed, he would need to compromise when planning team leadership roles for 2019 as it is expected Froome will want to return to try to win the Tour for a record-equalling fifth time.
However, Thomas has had a special bond with boss David Brailsford through his track days and on to the road, and with the rest of the team.
"A lot of people been there from the start like Fran Millar, Rod Ellingworth who was coaching me in the academy," Thomas continued.
"It's been like a family for me. I've certainly spent a lot more time with them than my own family in the last 10 years. At the same time, I can be really honest and open, tell Dave anything on my mind. I feel comfortable doing that. That helps a lot."
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