The Knaresborough-based holding company owns three manufacturing firms which provide powder processing and production services to household name clients throughout Europe.
Phoenix Foods manufactures powdered drinks at its 100-strong factory in Corby.
Mike Kirby, managing director of Speciality Powders, told the Yorkshire Post: “This acquisition provides us with a route to market for products we manufacture at our plants in Yorkshire and the Netherlands.
“It provides us with what we think will be an engine for growth for our existing business as well as being a good business in its own right.”
The 53-year-old founded the business 15 years ago with just a telephone. Group turnover is now approaching £40m.
Phoenix’s turnover has grown from £8m to £14m under the leadership of David Manning and Andrew Ducker, who co-invested with Endless.
The Leeds-based private equity firm bought the company in 2008.
Darren Forshaw, co-founder of Endless, said: “Phoenix Foods was one of the oldest investments in our portfolio and one of the last investments in our first fund.
“We have been delighted with the company’s performance, with the business growing consistently throughout the recession, demonstrating its strength and resilience.
“There is a powerful strategic fit with Speciality Powders.”