Where is this being mounted? I've done exhaustive searches for this type of fan in the past, and it seems they do not exist, however, I've never seen any 140mm case fan location that did not also already have a 120mm mounting hole pattern there as well. I've mounted more than 15 different 140mm fans with 120mm mounting patterns on a variety of different cases that were designed to use "up to" 140mm fans in specific locations and they ALL have supported also using a 120mm fan, or a 140mm fan with a 120mm mount, in those locations as well.
It would be helpful to know WHY it has to be 140mm, as I have never encountered a case that ONLY had 140mm mounting holes in any given location.