Freshfields Bruckhaus Deringer and Bird & Bird have advised on a landmark 3G sharing agreement between mobile operators 3 UK and T-Mobile, which will save the companies more than £2bn.

Freshfields acted for longstanding client 3, fielding a team under finance co-head Perry Noble and technology, media and telecoms partner Natasha Good. The Freshfields team worked alongside in-house lawyers Stephen Lerner, Kate Copping, Belinda Fawcett and Pip Zame.

Bird & Bird was instructed by T-Mobile, fielding a team led by relationship partner Graeme Maguire. The team supported T-Mobile's in-house lawyers, led by Robyn Durie and Matthew Redding.

Mobile operator 3 is a subsidiary of Hutchison Whampoa, which has been a client of Freshfields for around 10 years. Noble and Good advised on its $11.1bn (£5.7bn) sale of a controlling stake in subsidiary Indian mobile network Hutchison Essar to Vodafone early last year.

T-Mobile has used Bird & Bird on various intellectual property issues in the past, including a patent infringement claim relating to the supply of BlackBerry devices.

In this deal, the telecoms companies have signed up to a joint venture to combine their 3G networks, bringing almost complete coverage for 3G services across Britain by the end of 2008. The venture will increase both operators' 3G network coverage and bring cost savings of around £2bn over 10 years.