Sixth Street Partners, a private equity firm, completed a minority investment in Aquiline Capital-backed Fullsteam Holdings, a payments technology and vertical software company. Financial terms were not disclosed. "We believe the future of payments delivery is with integrated software. We're at the cutting edge of integrated payments processing and with the full support of Aquiline, and now Sixth Street, we are excited to continue to drive better solutions for our growing base of small and mid-sized business customers that are the life blood of our economy," Michael Lawler, Fullsteam CEO.