Virgin Money has been title sponsor of the race since 2010 and set a target of helping runners to raise £250 million for charity over the five years.
Many of the 36,000 runners in London on Sunday wore black ribbons to honour the victims of the Boston Marathon bombings a week ago, lending an extra poignancy to an event which has become a popular feature of the sporting calendar.
Ethiopia's Tsegaye Kebede and Kenyan Priscah Jeptoo won the men's and women's elite events on Sunday.
Joggers inspired to take up the challenge to run 26 miles through the capital can register online for the 2014 London Marathon from next Monday.
Virgin Money is the banking business of entrepreneur Branson's stable of companies. It is dropping its sponsorship of Premier League club Newcastle United at the end of the season.