News of the World says United boss Sir Alex Ferguson is an admirer of the highly-rated Porto star.
Ferguson is reportedly looking to strengthen his forward line in the January transfer window.
Hulk has a clause in his contract with Porto that says he cannot leave the club for less than 100million euros.
“The big clubs in England have been in contact,” said the player’s agent Teodoro Fonseca to News of the World.
“They have asked for details about his contract situation but any decision about his future rests mainly with the directors of Porto.
“I am calm about the situation and so is the player because he has an excellent future. I think we could be discussing a move in April or May.”
