You can initially set your auction's AutoExtend settings while defining bid controls. However, you can still enable AutoExtend (if not enabled initially) or modify your initial AutoExtend settings after the auction opens for bidding if you selected "Allow manual extend when negotiation is open" while setting the bid controls.
If your auction enters AutoExtend mode, you can change the number of times that the auction can AutoExtend, but you cannot change any other AutoExtend settings.
You cannot enable or modify AutoExtend settings for an auction that is in a preview period or has closed for bidding.
To change your auction's AutoExtend settings:
Under Your Negotiations at a Glance on the Negotiations Home page, click the number for the negotiation whose AutoExtend values you wish to change.
On the negotiation summary page, select the Extend Auction option from the Actions menu and click Go.
On the ExtendAuction page, review your current AutoExtend settings (if any). You can also review and extend your auction's scheduled close date and time. You can modify the following AutoExtend options:
Lines you want to AutoExtend (AutoExtend all lines, or only those that receive bids during the AutoExtend period)
Number of extensions allowed
Length of each extension
Start time of each extension (at the scheduled auction close time, or upon receipt of a new winning bid)
Once you have made your changed, click Apply .