Kawecki had worked for Giant UK Ltd for ten years.
He said: "After much consideration I have made the very difficult decision of stepping down from my position at Giant, a position I have enjoyed. Family commitments, amongst other things, guided me to this decision.
Kawecki jointly managed Giant UK along with Ian Beasant as the sales and marketing director.
Beasant will take full charge when Kawecki leaves on March 31st.
15 years with Giant, Beasant said: "Naturally, we are all sad to see John leave, but fully understand his reasons.
Giant has a major part to play in the competitiveness and success of todays IBDs. We are focused on constant improvement in service, product and partnerships. The next few years are crucial and very exciting times for Giant and our dealers.
The Giant Dealer conference 2006 runs from March 26th 29th at the Belfry Birmingham.