Sir Alex Ferguson is an admirer of the Porto star and wants to
strengthen his forward line as he bids for a fourth successive
Premier League title.
The Brazil international has a clause in his contract that says
he cannot be released for less than 100m euros, but sources at the
Portuguese club say a realistic offer of around £20m would see Hulk
leave the Estadio do Dragao at the end of the season.
"The big clubs in England have been in contact," said the
player's agent Teodoro Fonseca.
"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."
Hulk, 23, whose real name is Givanildo Vieira de Souza, has four
years left on his contract and is also rated highly by Arsenal boss
Arsene Wenger.
The Frenchman saw him play at the Emirates in last season's
Champions League but would almost certainly be outbid by
United.
Fergie is believed to like the physical attributes the striker
could add to his side after he lost Cristiano Ronaldo and Carlos
Tevez last summer.
Hulk made his Brazil debut against England in November and now
has two caps. He is likely to be named in his country's World Cup
squad.
He got his nickname because of his stocky appearance and his
likeness to actor Lou Ferrigno, who played the comic book hero.
"Hulk would be a good investment for United," said a Porto
source. "He has the quality to be a superstar in England and
his club will have no choice but to take a big offer for him very
seriously."