Dunnhumby is likely to become a 100%-owned subsidiary of Tesco this year, The Grocer has learnt.

Founders Clive Humby and Edwina Dunn were set to step aside, sources close to the chief executive and chairman said, while Simon Hay, the recently repatriated chief executive of Dunnhumby's US joint venture, would take over as chief executive of the group. Hay joined Dunn­humby in 1991 and returned from a six-year stint in Cincinnati in September.

Tesco currently owns 84% of Dunnhumby, whose founders pioneered the concept of Clubcard, and have run the scheme since it was introduced in 1995.

Dunn, Humby and Hay are the only registered directors not from the retailer. Tesco marketing director Carolyn Bradley became a director last September and Tesco's Richard Brasher, Andrew Higginson and Lance Batchelor are also Dunnhumby directors.

In a sign of further change at Dunn­humby's UK HQ, Martin Hayward, head of strategy and futures, though not a registered director, left the business this week. He declined to comment on his departure.

Meanwhile, Dunn­humby's US venture, which is 50% owned by US retailer Kroger, is understood to be preparing to float. The flotation would remove one of the main obstacles preventing Dunnhumby working with Tesco's US business Fresh & Easy on a loyalty scheme.

"We may work with Fresh & Easy, possibly on loyalty," Dunn told US website Supermarket News last week. "I couldn't commit to whether it would be on a loyalty programme that's confidential."

One senior insider told The Grocer: "Tesco is looking for some kind of solution in the US."

Although Kroger's loyalty scheme is run by Dunnhumby, this would not necessarily prevent it working with Tesco. "With Tesco and Kroger there is little overlap so it might not be a problem."

Dunnhumby declined to comment on whether Tesco was about to gain full control of the business.