Hulk has an £85million buy-out clause in his contract, but his Portuguese club are prepared to renegotiate and accept a fee of 40m euros (£34m) after the 25-year-old asked if he could leave.
Chelsea also plans to bring Magpies midfielder, Cheik Tiote, 25 to Stamford Bridge this summer.
Chelsea may pay close to 20 million pounds for Ivory Coast midfielder Tiote, who joined Newcastle from FC Twente two years ago.
The Toon goalkeeper, Tim Krul, 23, is also in the pipeline.
The west London club could bid as much as 10 million pounds for Dutch goalkeeper Krul.
