Chelsea target Hulk has a €100 million buy-out clause. REUTERS

Chelsea have stepped up their pursuit of FC Porto's Hulk, after the player's agent revealed the striker was interested in a move to the Premier League.

Hulk played under current Blues' boss Andre Villas-Boas at Porto and has been heavily linked with a move to Stamford Bridge since his former mentor made the switch in June.

However, Chelsea could face competition for the Brazil international's signature, with a host of top European sides - including Inter Milan and Manchester City - also interested.

And Hulk's agent, Teodoro Fonseca, said Chelsea could be forced to stump up an astronomical fee to land the highly-rated 25-year-old in January.

"Hulk at Chelsea? Anything is possible," Fonseca told A Bola. "But his buyout clause is €100 million, so his future depends on an agreement between the clubs.

"Hulk would wholeheartedly agree to work with Andre [Villas-Boas] at Porto or Chelsea, or at any other team, because he really likes the way he coaches. Andre knows Hulk very well and they have a good relationship."

The Chelsea-target has scored seven goals in 11 appearances for Porto this season, with the defending champions level on points with Benfica at the top of the Portuguese league.