It's a particularly bad piece of writing:

The airlines are positioning themselves to take advantage of “open skies”, which will liberalise transatlantic travel from next March. The change in rules will allow any airline to operate from Heathrow, the main transatlantic hub, to the US.

Bmi is not allowed to fly this route at present but plans to launch a US service. It is seeking a code-share so it can put bmi passengers on to United flights leaving London for New York, Washington DC, Chicago, Los Ange-les and San Francisco.

This will allow the airline to use its existing Heathrow slots for US flights without buying numerous new aircraft. Bmi has plans to purchase four new jets to service the Heathrow-JFK route, but it is unlikely that they will be available before open skies begins in March.

"Bmi is not allowed to fly this route at present but plans to launch a US service." What does "this route" mean? I suppose the writer means routes(plural) from Heathrow. There is, however, no United flight to New York for bmi to put passengers on.

And how does bmi code-sharing with existing operators' flights mean that they are "using (their) existing slots for US flights"? If they are simply code-sharing UA flights, then they won't need to use any of their slots. Surely, it is UA that will code-share with bmi (or so bmi hopes) on the routes that it (bmi) hopes to operate?

Then the writer tells us that bmi plans to purchase four new planes to service the LHR-JFK route. I presume he means us to understand that the planes will not have arrived by the time the open skies agreement starts. It really doesn't matter whether or not bmi has them before it begins, as they wouldn't be able to use them for transatlantic services anyway.

Sorry to sound pedantic, but it is just this sort of hotch-potch which ends up telling us nothing, other than that the writer doesn't really know what he is talking about.