The UK Competition and Markets Authority has just published its final order requiring Ryanair to reduce its 29.8 percent shareholding in Aer Lingus to max of 5 percent - Ryanair has called the decision "ridiculous."

In its ruling, the Authority says it will ensure implementation of the order interacts effectively with the current bid process by IAG for Aer Lingus and with assessment of the bid by European Commission.

According to the Authority, a key element of its decision was the ability of Ryanair to determine whether the IAG bid for Aer Lingus succeeds.

The Chairman of the Authority’s Ryanair/Aer Lingus Review Group states: “It’s not good for competition when one company holds such an influence over the future of one of its major competitors.  Although at this stage, Ryanair has yet to decide whether to sell its shares to IAG, we need to ensure that, whatever happens in relation to this particular transaction, Ryanair’s ability to hold sway over Aer Lingus is removed.”

Ryanair, which lost a UK Court of Appeal challenge to the Competition Authority’s original ruling, had asked the Authority to review its decision in light of IAG’s bid. The airline has said this morning that it will appeal today's "ridiculous decision" to the Competition Appeal Tribunal.

In a statement a Ryanair spokesperson, Robin Kiely said, “Today’s CMA decision rejecting Ryanair’s request to review its order to divest Ryanair’s 29.8 percent minority stake in Aer Lingus is manifestly wrong and flies in the face of the current IAG offer for Aer Lingus."

The statement continues: "When the only basis for the CMA’s original divestment ruling was that Ryanair’s minority shareholding was or would prevent other airlines making an offer for Aer Lingus, the recent offers by IAG for Aer Lingus totally disprove and undermine the bogus theories and invented evidence on which the CMA based its untenable divestment ruling."