ECI Partners, a UK mid-market private equity group, has made more than eight-and-a-half times its investment selling ClarityBlue, a marketing database company, to Experian, the credit-checking agency of UK retailer GUS, for £85m (€124m).

The private equity group acquired ClarityBlue in 2003 by funding a £10m management buy-out from Nasdaq-listed Sand Technology. It installed Andrew Vaughan, previously chief executive of Workplace Technologies, as chairman.