In an interim statement, the London-based company says that tough financial market conditions have gone on longer than expected, with third quarter equity market volumes dropping further.

"This has resulted in Fidessa's customers becoming yet more cost constrained and it seems unlikely that there will be significant improvement in the short-term," says the vendor, meaning 2012 revenues will be flat on the £278.3 million reported for 2011.

Although the equity markets are looking gloomy, the derivatives markets are more positive, and development spending is being increased to take advantage. This will contribute to margin being "slightly below that seen in recent years".

Analyst Investec has stuck with its 'sell' position on the vendor, explaining: "We see Fidessa as a high quality business but in the near and medium term we struggle with the valuation vs profit growth."

Shares in Fidessa were down 45.5 pence, or 3.3%, at 1326.5 pence per share, in mid-morning trading.