West Ham United is delighted to announce the signing of defender Matthew Upson from Birmingham City for an initial fee of £6million.

In a deal that could rise to £7.5million depending on appearances, the 27-year-old England international has agreed a four-and-a-half year contract at Upton Park to become Alan Curbishley's sixth signing during the January transfer window, and will go straight into the squad for our Premiership clash at Aston Villa on Saturday.

Born in Suffolk in April 1979, Matthew was spotted by Luton Town as a youngster and joined the Hatters as a trainee, but made just one senior league appearance for the club - as a 17-year-old against Rotherham United in August 1996 - before Arsenal paid £2million the following year to acquire his services.

After waiting patiently for his big chance under Arsene Wenger, the 6ft 1in central defender won a Premiership title medal in 2001-02, but continued to find first-team opportunities limited at Highbury, and headed out for loan spells with Nottingham Forest, Crystal Palace and Reading, before Birmingham City paid £1million to make him a permanent signing in January 2003.

The former England under-21 international played a key role as Blues retained their newly-acquired Premiership status at the end of the campaign, and he was then rewarded with a call-up to the full national team, making his debut in a friendly against South Africa in Durban on May 22, 2003.

He went on to win seven full caps under Sven-Goran Eriksson, the last of which came in a 1-0 friendly defeat against Spain at the Bernabeu stadium in November 2004, and has been a key performer for Birmingham City during the past four years, making almost 130 league and cup appearances and helping the club into the automatic promotion positions this season in their bid to return to the Premiership.

Exclusive reaction from Matthew Upson and Alan Curbishley to follow…