Erik Huseklepp has made the switch from Pompey back to his former club Brann in a four-and-a-half-year deal.
The winger made 28 appearances for the Blues after signing from Bari last summer.
Known affectionately as ‘Erik the Viking’ by fans, Huseklepp scored six goals in Pompey colours, the most memorable a stunning injury-time volley to secure a 1-0 win over Blackpool at Fratton Park last September.
The Norwegian international netted a double in a 3-0 win at Peterborough in January, but soon joined Birmingham on loan as financial troubles engulfed Pompey.
Blues boss Michael Appleton said: “Erik was a regular in the side before the situation changed dramatically here and he had to go out on loan.
“He was unlucky because after playing regularly for us things didn’t quite work out for him at Birmingham.
“I think Erik feels going back to play in Norway will be best for his international career, and we wish him all the best."