German carrier Air Berlin is intending to join the Oneworld alliance, and has reached a preliminary agreement on membership.
Air Berlin's bid is being sponsored by British Airways. It has also entered codeshare pacts with Oneworld's American Airlines and Finnair.
The German carrier says it has agreed on "key aspects" of its prospective accession to Oneworld and "will work towards completing a full membership agreement".
"Membership in Oneworld would strengthen Air Berlin's competitive position and enable it to participate in the alliance's revenue-enhancement and cost-reduction activities," it adds.
Air Berlin's tie-up with American will allow it to offer codeshare flights to 15 additional US destinations, plus two in the Bahamas. The Finnair partnership will provide codeshare access on routes to points in Europe and Asia.
Germany's main carrier, Lufthansa, is a central member of the rival Star Alliance.