The club thanked Koszary for his work in “rebuilding the commercial fortunes of the club” since 2013 as well as for being “instrumental in creating various charity partnerships”.
In the statement, which can be read in full HERE, Bairns chairman Gary Deans said: ““Kieran has become a familiar and popular face around Falkirk FC and his enthusiasm will be missed by those who have worked with him such as colleagues, sponsors and partners.
"I would like to thank Kieran for all his work and in particular over the last 15 months or so as we have managed through the challenging pandemic period.
"I hope we see Kieran and his family at the Stadium enjoying the football as fans in the coming years.”
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Koszary also commented, saying it was the right time for him and the club to part ways.
He said: “The last eight years have been an extremely fulfilling and intense period of my life and I think it is genuinely the right time for me and the club to move on to a new chapter.
“I have grown to love the club and the Falkirk family, and I have had some amazing times and memories from my time at The Falkirk Stadium.
“I have worked with a fantastic group of people, staff, players, coaches, volunteers and directors and I thank every one of them for making this job such an enjoyable one.
“I would also like to thank the partners I dealt with daily and also the supporters who have got behind the various initiatives at the club and shown a fantastic level of commitment.”