There could be several reasons for withdrawing a reverse auction. Maybe you have found or received a better offer from another vendor who is not on your participation list. Or, you don't need the items after all.
To withdraw a reverse auction, do the following:
Open the Reverse Auction window:
In the Reverse Auctions window, in the No. field, select the reverse auction you want to withdraw.
Click Functions, Withdraw.
A window pops up asking you to confirm your withdrawal.