The Arthur Guinness Fund will award grants to social entrepreneurs that will total about £6m by 2012.
The fund has also announced a three-year partnership with Ashoka, a global association of more than 2,500 social entrepreneurs.
With Ashoka’s help, the fund will select 30 candidates over the next three years. Those chosen will receive financial, practical and strategic support to run projects that bring about social change.
A spokesman for the Arthur Guinness Fund said he was unable to confirm the average size of the grants it will award because they varied so much.
According to its website, the fund picks candidates who are "fiercely committed to their idea and dedicated to refining, testing and spreading their vision".
The fund was set up in 2009 in memory of Arthur Guinness, founder of the Guinness brewery business. It is funded by Guinness & Co and has awarded funding to projects in the UK, Ireland, Africa, Indonesia and the United States.
Bill Carter, senior vice-president of Ashoka, said: "The social entrepreneurs create deep and lasting impact in their communities and inspire future generations along the way.
"With the support of the Arthur Guinness Fund, Ashoka will be able to welcome even more of these leading social entrepreneurs into our community and demonstrate the world over that everyone, not just an elite few, can create positive and lasting change."
The application process for the grants starts on 28 September. To apply, go to www.guinnessforgood.com.