France Telecom’s mobile unit, Orange, has integrated Microsoft’s flagship mobile OS with its own billing platform, allowing users of Windows Phone 7 devices to add the cost of content purchased to their mobile phone bill.

The functionality made its debut in France this week and will launch in the UK in the near future. The offering allows users to tack on charges for all content purchased in the Windows Phone Marketplace to their Orange bill. Orange is the first operator in Europe to integrate carrier billing with the Windows Phone Marketplace, but the subject was a popular one during conversations in Barcelona last week.

Xavier Perret, VP of strategic partnerships at Orange, said: “It is a new step forward in our partnership with Microsoft on Windows Phone 7. It will allow our customers to enjoy the real benefits of their content purchases from the Windows Phone Marketplace by offering them a simpler and more secure payment method.”

In related news, UK operator O2 has tapped up mobile payments provider Mi-Pay for a range of automatic top up services to be offered to the carriers eight million prepay customers.

Mi-Pay will deliver weekly or monthly and low balance auto top up services to O2 customers from this week.

Allan Jakobsen, CEO of Mi-Pay, commented on the deal, saying: “Many of our existing operator clients have realised significant revenue benefits from supplementing ad hoc prepaid top-up with regular and low-balance top-up options,” which Jokobsen claims to drive higher levels of ARPU.