Poker giant PartyGaming is celebrating the announcement that it will be the first web-based firm to join the FTSE 100 Index since the dotcom boom.
PartyGaming, which floated on the London market in June, was odds-on for promotion despite the shock of seeing more than £2 billion wiped off its value on Tuesday.
The company is to replace recruitment firm Hays following the quarterly reshuffle of the Footsie, with oil and gas group Cairn Energy restored to the top-flight after a six-month absence at the expense of media firm Emap.
PartyGaming was worth £4.2 billion on the basis of Tuesday's closing prices which determine the changes to membership of the Footsie - more than established names such as British Airways and electricals retailer Dixons.
Its elevation comes just 24 hours after its shares slumped by a third on a warning about the future growth of the online gaming market. In addition to PartyGaming, companies that recently listed on the London Stock Exchange also accounted for major movements in the lower tiers.
Those entering the FTSE 250 Index include satellite operator Inmarsat, Mr Kipling cake maker RHM and property investor Mapeley.
Filter paper manufacturer Whatman and telecoms firm Kingston Communications were demoted.