British mobile operator Vodafone will become the third to start retail sales of the Apple iPhone.

“Vodafone and Apple have confirmed that they had reached agreement to start selling the iPhone 3G and iPhone 3GS in the United Kingdom and Ireland at the beginning of 2010,” – official press release says.

Vodafone has already started pre-registration of those willing to buy the popular devices, promising to publish the tariff plans and complete terms of sale later.

The other day another UK operator – Orange (owned by France Telecom) – announced it has reached an agreement with Apple to start selling the iPhone in the UK at the end of this year, without disclosing an exact date.

Introduction of two new iPhone operators will put an end to the O2 monopoly for iPhones retail sale and service in the UK.

iPhone was put on sale in the UK in November 2007. It can be bought in Apple or in Carphone Warehouse mobile shops, or in O2 shops (currently the largest mobile service provider in the UK owned by Spanish Telefonica). Meanwhile, all iPhones are intended for use only in O2 network.

Meanwhile, O2 is not going to give in and will continue selling iPhone. It has already announced that O2 will be an exclusive distributor of a new multimedia smartphone Palm Pre which is called by some market experts an “iPhone killer”