SHARES in Iona Technology traded up strongly on the group's first day of trading on the Nasdaq market in New York, and closed up $4 from the initial public offer price of $18 a share. At $22, Iona has a stock market value of $407 million (£254 million).

A spokesman for lead underwriter Lehman Brothers said that the 7.65 million shares offered in the IPO had been 10 times oversubscribed and there had been heavy trading in the shares when the market opened. The shares traded up as high as $23 1/4 before settling back to a band between $21 1/2 and $22. The $22 share price values chief Dr Chris Horn's stake in Iona at over £57 million.