The group told analysts that it had been forced to delay the release of Soul Reaver, part of the popular Legacy of Cain series of games for the Sony Playstation, from June to July.
The news coincided with an announcement that the company's founder and non-executive chairman, Stephen Streater, had resigned with immediate effect.
Eidos emphasised that Mr Streater had founded Eidos in 1990 as a 10-man company exploring video compression technology. It was only five years later that Charles Cornwall, the chief executive, bought two games companies and forged Eidos' new identity.
The shares, which on Wednesday were included for the first time in the FTSE 250 index of mid-cap companies, have trebled in price since October. Yesterday they fell from 2,312.5p to 2,107.5p, wiping more than pounds 35m from the group's market value.
However, analysts attacked the City's reaction. One said: "This is ridiculous: really this is all just about one game."Reuse content