The answer is a definite yes.
To see why, consider that there are four dimensions to the whole ticketing process.
The operating carrier...
...need not be the marketing carrier...
...who need not be the fare owning carrier...
...who need not be the ticket issuing carrier.
So you could theoretically have a BA 125-stock coupon issued under a fare filed by American Airlines and valid for travel on a US Airways marketed flight operated by Qatar Airways.
JAXBA - can the validating carrier be different to the ticketing issuing carrier?