London-headquartered ChartCo began making charts for the Royal Navy more than 250 years ago and now provides data to over 12,000 vessels worldwide, from super-yachts to freight ships. It is the world's largest provider of navigational data and nautical charts.

ChartCo is part of the maritime navigation systems company Kelvin Hughes, which is in turn backed by ECI. Last year ChartCo had revenue of over 40 million pounds.

Equistone was formed in 2011 following a management buyout of Barclays Private Equity. Tim Swales, Partner at Equistone, said ChartCo would continue to grow organically and through acquisitions.

(Reporting By Freya Berry, editing by David Evans)