The Wellcome Trust, Britain's largest charitable foundation, is launching its first bond - in order to raise cash to invest in scientific research.
The trust's portfolio has seen strong returns
It is the first public bond to be launched by a UK charity, following the lead from US organisations.
The organisation hopes to raise some £300m to £500m ($551m to $920m) when it issues the 30-year bond in the UK.
The trust's funding of biomedical research is second only to that of the Bill & Melinda Gates foundation.
Rating agencies Moody's and Standard & Poor's have rated the bond a triple A.
Bonds which are rated AAA are judged to be of the best quality and carry the smallest degree of investment risk.
It is the first time Moody's has rated a charitable trust's bond in the UK.
The Wellcome Trust's investment portfolio, which had £12.3bn ($22.66bn) in September 2005, has seen average returns of 9% a year over the last decade, says rating agency Standard & Poor's.
Such strong returns mean it should not be hard for the trust to raise money.
Research areas at the trust have included the human genome, bird flu and malaria.
"[The move] gives us greater balance sheet flexibility, and should enhance our mission, which is promoting and fostering research with the aim of improving human health," said Danny Truell, the trust's chief investment officer.