Ubercart Recurring Payments and Subscriptions:Charge automatically?
You can use this module.

UC Recurring Payments and Subscriptions

Features:

New/improved API for payment gateways to interface with uc_recurring - see hook_recurring_info().
Ability to treat a recurring fee as a new order - so it gets access to everything a new order gets at the time of renewal e.g separate invoices, apply roles etc...
Option for unlimited renewals (ie: renew until canceled).
Option for recurring payments to be set that same as product price (this means that the recurring payments can be based on adjustments of a products from things like attributes).
Conditional action support - sending emails on failed renewals.
Extension API - administrators can configure what will happen on a failed payments, e.g order can be extended and re-attempts as many times as required.


Take a look at discussions here 

PayPal community

x.com

Please note module is not stable yet