Businessmen David Gold and David Sullivan, former owners of Birmingham City, completed their takeover of the Premier League strugglers and said they wanted to take the club into the Champions League within seven years.
They also plan to move West Ham from Upton Park to the new Olympic Stadium just three miles away after the 2012 London Games.
Their immediate concern however was to keep the Hammers in the Premier League - the team are 16th and only being kept out of the relegation zone by goal difference.
Sullivan, who watched the team from the terraces as a boy, said in a tearful interview with radio station Talksport that he and partner Gold were lifelong Hammers supporters who always dreamed of owning West Ham.
"We care passionately about this club, we are so pleased to be here," he said, adding there were no plans to replace manager Gianfranco Zola.
"He is the manager and will stay as the manager," he said. "But we must stay in the Premiership, if we don't it is an absolute disaster for us."
SHADOW CLUB
West Ham may be one of London's biggest clubs but have mainly lived in the shadow of Arsenal, Tottenham Hotspur and Chelsea and have never won the title in their 110-year existence, unlike the other three.
Hammers fans loyally maintain they "won" the World Cup in 1966 with their trio of Bobby Moore, Geoff Hurst and Martin Peters in the triumphant England team, and they have also enjoyed cup successes.
Three-times FA Cup winners, they lifted the European Cup Winners' Cup in 1965 but since 1978 they have been relegated from the top flight four times and have never finished higher than ninth since regaining their Premier League place in 2005.
However, they have long been admired for their attractive footballing philosophy, introduced by Ron Greenwood in the 1960s and maintained by the eight men who have followed him as manager in the last 36 years.
Sullivan wants to maintain West Ham's traditions and take them to the heights of the English game.
Other rich owners who have taken control of the clubs they supported as boys have tried and failed in the past but Sullivan and Gold believe a bright new future awaits.
"West Ham is the club of the East End and Essex. I went to school in Hornchurch and right out into Essex is West Ham land," said Sullivan.
"It is 30 miles but we hope all those people who live there and feel passionate, get behind the club. We will not make the mistakes others have made in the past."
