Postiga's career statistics

The �5m deal takes Postiga, 21, back to his former club, after spending just over a year at Spurs.

Going the other way is 25-year-old midfielder Pedro Mendes, for whom Tottenham have agreed a �2m deal.

Postiga, who scored his only goal at Euro 2004 against England, struggled to settle in the Premiership, scoring just twice in 22 appearances.

Spurs sporting director Frank Arnesen told the club's website: "There is no doubting Helder's ability but maybe he came to the Premiership too soon.

"He was keen to return home and, although we rate him highly here, we did not like to see him unhappy.

"He has always been a model professional during his time here and we wish him well for the future."

New Spurs arrival Mendes is a versatile player who made five appearances in the Champions League for Porto last season.

I like to think I'm quite an all-round midfielder Pedro Mendes

Arnesen added: "It is an excellent deal for us because Pedro gives us more options in midfield and brings with him experience in European competition.

"He has a well deserved reputation on the continent and we are delighted to have added him to our squad.

"I hope that the Spurs fans will take to him very quickly."

I am so gutted about Postiga right now as I was so confident that he would do well this season From Jermain DeMo Have your say on 606

Mendes admitted the move took him by surprise, but says he is "looking forward to a good career at Tottenham and helping the club to success".

He added: "I wasn't expecting this change but I'm very happy to be here.

"I think Tottenham is a great club and the Premier League is a championship I like very much.

"I'm a central midfielder - defensive and attacking - I like to think I'm quite an all-round midfielder.

"I'm anxious to start pre-season, to start training with my new team-mates and to get to know them. I'm really looking forward to the challenge."