A US investment group has taken a stake in Iona Technologies, the successful Irish software company that recently floated on New York's NASDAQ exchange, documents from the Securities and Exchange Commission showed last night.

Zweig DiMenna International, which includes Gotham Advisors, purchased 5.3 per cent of the company's shares at between $15.38 (£10) and $22.57 (£14) a share. The total investment, according to the SEC. documents, came to about $19 million.

Iona, based in Dublin and headed by Mr Chris Horn, makes the Orbix family of software.