Wouldn't work, IMO. If there were a cross-licensing agreement, I would find it difficult to believe that the terms of the license would extend to companies, affiliates or merged partners occuring "after the fact".
Look at HP, Agilent and Verigy. HP owns a majority interest, I believe, in spin-offs Agilent and Verigy, yet they had to buy their own licenses.
So, IMO, possible, but not likely.
SGE