BA are not interested, and are in fact trying to offload slots at present.
This is not true. BA has moved a tranche of s/h flights from LGW to LHR for the winter season precisely to ensure they don't lose slots at LHR.
When times are bad, people think this is how it will always be. Just as people do in the good times. Demand will return. If LH really is intent on selling BD, the directors of BA would be negligent in not giving the opportunity very serious consideration.