Samsung has opted to launch the new handset in Europe ahead of other markets
Samsung has unveiled its latest flagship smartphone - the Galaxy S3, reports the BBC.
The handset has a 4.8 inch (12.2cm) screen, an increase on the 4.3 inch screen of its predecessor.
The firm described it as the "best in class" Android-based smartphone on the market.
Analysts say the popularity of the previous Galaxy - the S2 - was a major factor in the firm overtaking Nokia to become the world's best-selling mobile phone maker.
Other features on the S3 include an 8-megapixel camera on the rear, and a 1.9MP front camera for video calls.
The firm also utilises what is described as a "natural language user interface" dubbed S Voice. The South Korean company said it was a major improvement on the voice control features it included on earlier models.
"It is more like a good friend and listens intently and responds effectively to you," a spokesman said at the launch event in London.
The facility can be used to command the phone to play songs, adjust the volume, send texts or emails and take photographs.
The function is likely to be compared to Apple's Siri software, introduced on its iPhone 4S.
The S3 will be available in two colours, pebble blue and marble white, and the firm says that other options will be available at a later date.
The new handsets will be available from the end of May in Europe. Launches in Asia, the Middle East and Africa will follow.
A 4G version will go on sale in the US and South Korea in the summer.