Britain's IAG, the owner of British Airways, earlier this year sold its stake in Norwegian and said it was no longer interested in an acquisition.

Citing "sources in the market", the Expansion report said investors are taking positions in Norwegian Air ahead of a possible takeover. The report did not give further detail.

Shares in Norwegian Air were trading up 14% at 1204 GMT after rising as much as 28% earlier in the session.

IAG declined to comment. Norwegian Air was not immediately available for comment.

(Reporting by Terje Solsvik and Victoria Klesty in Oslo, Alistair Smout in London and Belen Carreno in Madrid; Editing by Gwladys Fouche and Deepa Babington)