Vodafone and Microsoft have signed a deal to provide instant messaging on mobile phones.

A new service, due to go live before the end of the year, will let users see each other online and exchange instant messages between PCs and mobile phones. It is hoped the service will bring together the 165 million MSN Messenger users with Vodafone's 155 million customers.

Instant messaging has a couple of advantages over SMS. Instant messages arrive faster than SMS text messages, and users can see who's online.

Unlike free PC-to-PC instant messaging, the PC-to-mobile phone service will have a price, which the companies have not yet disclosed. Vodafone customers will pay for the instant messaging service either through their monthly bill or prepayment, while MSN Messenger customers will be able to pay through packages available in connection with Messenger.

The deal reflects a growing trend in the wireless industry toward operators hooking up with big brand names in the IT sector to push Internet-style services on mobile phones, such as instant messaging and Web surfing.

On Wednesday, rival T-Mobile said it is abandoning its own mobile T-Zone portal on devices to use the search engine of Google as the home page as part of its new range of mobile Internet services.