The Wellcome Trust has announced plans to commit up to £5bn to its “charitable mission” over the next five years.

The announcement follows a strong year for the charity which saw a return of 6.1 per cent on its investment portfolio in the year ending 30 September 2015.

The figure equates to an additional £1.1bn on its investment portfolio value of £18bn at the start of the year.

Baroness Manningham-Buller, chair of the trust, said: “Once again, our investments have done well, building on past investment decisions, and despite a difficult market.

Manningham-Buller thanked former chair Sir William Castell “for his strong and thoughtful leadership”. Castell retired from the post in September.

“During his time, the portfolio rose in value from £13.1bn to £18.3bn and we have given £6.9bn to fund our charitable activities,” she said.

Since the inception of its investment portfolio in 1985, the charity has provided a total return averaging 14 per cent a year, according to its latest set of accounts.

Danny Truell, chief investment officer of the Trust, said: “Our internal investment team and external investment partners have again added significant value across the board, enabling us to perform better than global stock markets with considerably lower volatility.

"Prospective investment returns are now lower in most global markets, but with strength in breadth and depth across our investment team and the businesses and partnerships in which we invest, I am confident that we can continue to reinforce the Trust’s robust financial position.”

Cash payments by the Trust rose to £756m over the year, while its investment base rose to £18.3bn.

It now spends 35 per cent more a year than it did at the start of the global financial crisis in 2008.