Goldman Sachs:

The US merchant bank will invest via its GS Capital Partners 2000 fund, which raised $5.25 billion (€5.9 billion) from investors last year. The bank will also raise additional funds for the group.

Providence Equity Partners:

A US-based private equity firm that specialises in communications and media investments. It will invest via its $2.8 billion Providence equity partners IV fund. It has invested in Western Wireless, the main shareholder of Meteor, the third mobile provider.

Soros Private Equity Partners:

An affiliate of Mr George Soros's Soros Fund Management. The Hungarian-born billionaire turned philanthropist is aware of the Eircom bid but is not involved. Has $3.5 billion invested including a stake in Meteor.

Warburg Pincus:

Has more than $1.3 billion invested in 28 different telecommunications companies, including the Irish group Cognotec.