The HCT Group, a community transport social enterprise, has arranged a £3m loan deal in which investors will receive a return on their money based on growth in its turnover rather than flat-rate repayments.
The deal, called a quasi-equity loan, involves lenders sharing in some of the risk faced by the company, which is also a charity.
Lenders working on the deal said it was the biggest of its kind involving a UK social enterprise.
"We're trying to demonstrate that you can invest in social enterprises in a sustainable way," said Antony Ross, executive director of Bridges. "It's important to demonstrate to the market that you can lend money to social enterprises and receive a risk premium.
"There are a growing number of investors, charitable and private, who are willing to invest at below-market return, but who want their capital back. If we can demonstrate it can be done here, we can show it will work elsewhere."
HCT wants to raise another £2m.