What argument was made for a 300-seat airliner for Europe?

The Airbus programme formally took shape in 1965, when France and West Germany began talks on a joint effort to develop a high-capacity, short-range transport. At that year's Paris Air Show, Europe's major airlines set out their requirements for a new "Airbus" capable of carrying 100 passengers or more on short and medium stages at low cost. In September 1967, aircraft manufacturers from France, West Germany and the United Kingdom signed an initial memorandum of understanding to collaborate on developing an innovative large airliner.

It was recognised that if each European manufacturer launched similar aircraft onto the market at the same time, none would achieve the sales volume needed to make them viable. In the British case, production costs ran 10% to 20% higher than their American counterparts because of how short their production runs were.

The initial 300-seat concept, named the Airbus A300, drew limited interest from airlines, largely because the planned Rolls-Royce RB207 engine was still at an early stage of development and represented a significant risk. The partners then scaled the design down to a 250-seat version, first called the A250 and then the A300B, an airliner that could use existing engines.