The co-founder of Groupon and his wife have pledged to give away the majority of their wealth, signing Bill Gates and Warren Buffett’s Giving Pledge along with six other billionaires.

Eric Lefkofsky (pictured) and his wife Liz were among the latest tranche of Giving Pledge signatories this week. The pair are estimated to be worth around $1.75bn.

The Giving Pledge was established by Warren Buffett and Bill and Melinda Gates more than three years ago to encourage the world’s billionaires to pledge to give at least half of their wealth to good causes during or after their lives. So far more than 120 individuals, couples and families have signed up.

The Giving Pledge has traditionally been dominated by American philanthropists and this latest tranche is no break from that tradition. Four of the seven signatories are American, and more American based. Russian tech entrepreneur Yuri Milner, Indonesian entrepreneur, staunch Christian and table tennis enthusiast Dato’ Sri DR Tahir and Swiss-born Hansjorg Wyss are the non-American contingent.

Among the other signatories are hospitality tycoon Richard Edwin Marriott and his wife, and GoDaddy co-founders Bob and Renee Parsons.

In their pledge letter, the Lefkofskys said: “We recognise that perhaps our greatest accomplishment – with the exception of the kids we raise – will not come from businesses we’ve started, but from the help we provide to people and causes around the world.”

Like the other American pledgers, the Lefkoskys are already heavily involved in philanthropy and have their own family foundation.