Rival buy-out firms are joining forces to bid for Opodo in an effort to create Europe’s largest online booking service.

Axa Private Equity and Permira, owners of Go Voyages and Spanish online company eDreams respectively, are expected to confirm a joint bid for London-based Opodo today (Tuesday).

The are seen as front runners to acquire the internet booking firm put up for sale by Amadeus last year in a €500 million deal despite competition from US company Carlyle, owner of Spanish operator Orizonia.

It is thought that Expedia is unlikely to join the bidding for Opodo as offers are due to be finalised by today’s deadline. Axa and Permira aim to merge Opodo with eDreams and Go Voyages.

Axa bought Go Voyages for around €300 million last year after it outbidding Permira. Permira then beat Axa to buy eDreams for a similar amount.

Opodo saw its earnings before interest, tax, depreciation and amortisation rise by 46% to €28.6 million in the nine months to September last year with gross sales up by 13% to €1.19 billion.