Feyenoord defender Bruno Martins Indi has confirmed he is leaving De Kuip, with Porto set to clinch his signature.
Brazil defender Maicon hopes to commit his future to Roma after expressing his wishes to sign a new deal with the club.
Petrucci has started both of Posh's npower Championship fixtures since joining the club on an initial month-long deal on January 9.
The 21-year-old midfielder told the club's official website: "I am very happy. I only signed for a month in the first place because it was my first loan spell.
"I didn't know what to expect. However, since the first few days I realised that I wanted to stay for longer and I am very pleased to be here until the end of the season."