Euronext, which operates bourses in Paris, Amsterdam, Brussels, London, Lisbon and Dublin, said on Monday it was particularly attracted to Oslo Bors’ position in seafood derivatives as well as oil services and shipping.

The group said it had offered to buy Oslo Bors for 145 Norwegian crowns (US$16.58) per share, a 20.8% premium to the Norwegian firm’s last traded price on Friday.

It has already secured support for its offer from Oslo Bors shareholders representing 49.6% of outstanding shares, Euronext said in a statement.

The offer continues Euronext’s pattern of seeking modest acquisitions rather than a transformational deal that would put it alongside industry leaders such as CME, ICE and London Stock Exchange.

Euronext is heavily dependent on share trading for revenues and has taken steps to diversify by moving into foreign exchange and buying the Irish Stock Exchange (ISE), which lists bonds

Bigger rivals have also been expanding, with ICE completing its acquisition of the Chicago Stock Exchange and CME taking over NEX Group.