Honda chief Yusuke Hasegawa says the collapsed deal with Sauber is "very disappointing" for the Japanese manufacturers.
Honda, who have been the engine-supplier for McLaren since 2015, were reported to have had a deal in place to form a partnership with Sauber, who are bottom of the Constructors' Championship this season.
But, Sauber's former team boss Monisha Kaltenborn was replaced by Frederic Vasseur and the plug has now been pulled on the Japanese outfits power-unit being used at the Switzerland-based outfit.
The new man in charge has decided to stick with Ferrari for the 2018 campaign and Hasegawa admits the decision has come as real disappointment to Honda, who were hopeful of gaining valuable information from the new alliance.
"Of course it is very disappointing," he said. "It is a customer team program so it doesn't hurt our program very much, but we still expected to get the opportunity to get our engine running more.
"We would have got more data and been able to make comparisons, so it is very disappointing. More than that, on the practical side, we had to stop the preparation, so it is very bad."