Asset rentals in SAP

Hi Gurus,

We have a requirement where assets are rented out to different parties. Initially they are inventory items. When a agreement is reached with a party ( usually for one year) the inventory item is converted into an asset. The depreciation begins on asset. If customer decides to buy that asset within one year we have to convert it back into inventory, back out the depreciation and treat it as a sale of inventory item.

Note - If it is more than one year it can be directly sold ( asset sale). Under one year is the issue.

Any ideas on how to achieve this in SAP.