A new organisation, called the North East Social Investment Company, will be set up to run the fund, which will support the development and expansion of voluntary and community organisations and social enterprises.
The social investment wholesaler Big Society Capital has promised to invest £4.5m and the Northern Rock Foundation has committed another £3m to the fund. Both investments are subject to the completion of negotiations.
The remaining funds will be raised from foundations and high-net worth individuals with an interest in the north east, a spokesman for BSC said.
The company will be supported by a further £1.5m contribution from the Northern Rock Foundation.
Alastair Balls, chairman of the Northern Rock Foundation, said the North East Social Investment Company and its first social investment fund would "provide an innovative regional strategic solution" to develop social investment in the north east.
"This is an opportunity to create a seismic shift in the funding landscape of the voluntary, community and social enterprise sector in the region," he said.
Subject to completion of negotiations between Big Society Capital and Northern Rock Foundation, the company will be set up early in the new year and the fund is expected to open for lending by mid-2014.