(ShareCast News) - Shares in software developer TechFinancials lost almost a third of their value after the company issued a profit warning.At 0814 BST shares in the AIM listed company were down by 28.57% to 20p after the company said it would not meet the market's profit and revenue expectations for 2015.TechFinancials, which provides trading programmes for online brokers, said first half revenue increased slightly from $7.15m to $7.34m during the first half of the year."Operating performance improved marginally compared with the same period in 2014, but EBITDA, while positive, has been affected by an increase in necessary research and development expenditure," TechFinancials said.The company's business to consumer product OptionFair had a lower than expected rate of customer conversion due to management decisions and the cost of complying with new regulations, TechFinancials said."While the company has instigated changes to its management and operations in Cyprus to restore and improve its rate of customer conversion, the board does not believe that these changes will take effect in time to enable OptionFair to achieve its anticipated level of business," the update said.Chief executive Asaf Lahav said the group remained positive about long term prospects for the business to consumer segment.