The South Korean consumer electronics company will now partner the English Premier League club through to the end of the 2013/2013 season.
Samsung will continue to have the right to use Chelsea players and club imagery in its marketing campaigns.
It will also remain the club’s exclusive consumer electronic products, which includes providing digital cameras, mobile telephones and IT equipment.
No financial details have been disclosed but reports suggest that it is an improvement on the current £11m a year deal.
The club has a number of official sponsors including kit makers Samsung, Thomas Cook, Heineken and EA Sports.
Chelsea has been diversifying into hotels, restaurants, a travel company under the Chelsea Village brand since Roman Abramovich bought the club in 2003.
According to the latest Deloitte football rich list, the club generated £212m in revenues during the 2007/2008 season, second only to Manchester United in England.