The charity is working with the social lender Triodos Bank to raise a five-year bond that will pay 5 per cent fixed interest per year. Investors will receive their capital back at the end of the period.
The minimum investment is £2,000, except for GLL employees, who will be able to make a minimum investment of £200.
The bond will be used to help GLL develop two London 2012 Olympic venues in the Queen Elizabeth Olympic Park: the Copper Box arena, which hosted handball during the 2012 games, and the Aquatics Centre.
The facilities will be available to elite sportsmen and women and to local residents and community groups. The bond will also contribute to the restoration of the Royal Greenwich Lido in Charlton.
GLL is a charitable industrial and provident society. It was established 20 years ago and manages more than 130 public leisure centres and libraries. It had an annual turnover of £123m in 2012, according to its latest accounts.