Trading systems developer Fidessa said it recorded good growth since the start of the year but warned that overall markets are still expected to remain difficult for 2011."The challenges of uncertain regulation, macroeconomic environment and structural pressure remain within the financial community," the group said in a company statement.Nevertheless Fidessa, which supplies trading platforms to banks and financial institutions, said it signed significant new orders and maintained existing customers. Margins in the first half of 2011 are expected to be similar to that achieved in 2010. It said it continues to have a strong balance sheet with strong reserves, no debt and strong cash generation.Fidessa added that its offices in Tokyo, Osaka and Hong Kong remained fully operational throughout Japan's earthquake disaster."Whilst it is still early in the recovery process, at this point in time the events are not expected to have a material impact on the results for the year," the group said.CJ