Sage is not selling payments operations in other countries. Sage and GTCR, which says it has committed up to $350 million of equity capital to the SPS platform, have agreed SPS will be the preferred merchant processor for Sage clients in North America.

The North American payments business was a drag on revenue for the first half ended March 31. Without it, organic revenue here would have been up 7 percent, instead of 4 percent, according to Sage CEO Stephen Kelly.

GTCR said it will work with SPS management to grow the business and fund possible acquisitions in the payment processing industry.

"We intend to invest further in the technology and offer additional innovative solutions to SPS customers and partners," Collin Roche, GTCR's managing director, said in a prepared statement.