Service Contracts delay in start

My client sells products through distributors channel.  They want the service contract to not start until after the product is sold by distributor to the end-user.  Is there a standard out of the box functionality to address this?  Service start delay provides this functionality, but it is for a set period delay.  But, here the requirement is to start the service contracts on some sort of event driven activity.  Any help / suggestions would be much appreciated.

Thanks,

Ram Iyer