RE: IAE & AENAs I have suggested before such a merger would make sense - both IAE and AEN are good North Sea oil companies and both companies have projects that are very economic at current oil prices.
That said, with the large share issue last year for IAE, there are probably more oil reserves per share for AEN versus IAE. As a result, AEN will likely opt to sell down working interests in their projects to access the necessary financing rather than merge with a junior peer.
If a merger did occur, it would likely be a 1:1 share swap (approx. equal market caps). However, as AEN is consistently priced higher by the market than IAE investors may not be betting on a merger.