The Environmental Capital Fund has raised £135m to invest in clean energy projects around the UK.
Backers of the fund include a syndicate led by private equity giant Lexington Partners while SSE is taking an initial £13.8m minority stake.
SSE Pipelines currently has more than 130,000 gas connections and also connects new residential and commercial developments across the UK.
Calum Pateron, SEP managing partner, said the remainder of the fund will be used to invest in areas such as hydro power, energy efficiency, heat pumps and district heating schemes.
He said: "This is another significant fund for us, which helps to broaden our reach without undermining our core focus. The market opportunity for energy infrastructure finance is very attractive, and the new fund fits well with our existing activities."
Yesterday Gregor Alexander, SSE finance director, said: "We have identified a range of assets and businesses which are not core to SSE's future plans. This disposal represents the latest step in the programme to significantly simplify the SSE group and secure proceeds and debt reduction estimated to total around £1 billion."
SEP's Environmental Energies Fund bought a portfolio of clean technology businesses from SSE Ventures in early 2012 with that fund also backed by Lexington.