This raises other issues....
According to *A, you can call any carrier to issue the RTW. But according to mnay carriers, your first intercontinental flight must be on the issuing carrier.
When it comes to reissues, again *A says that anyone will do it. But in my experience, airlines want to pass the buck. (In one case, LH wanted me to go to SQ, as they were the next intercontinental segment. I wanted to keep my reservation on Appollo.)
What are the responsibilities for *A carriers? Can I have UA issue a RTW if none of the segments are on UA?