Pretty much correct. The Pratt engine was in service six or so months before the GE engine (and a year or so before the RR), and United was the 777 launch custo

Pretty much correct. The Pratt engine was in service six or so months before the GE engine (and a year or so before the RR), and United was the 777 launch customer. The only thing is that the newest 777 variants (777-200LR and -300ER) only offer GE as an engine option, there isn't even a RR choice.