Stockbroker Numis saw profits fall in the six months to 31 March amid uncertain economic and market conditions.Pre-tax profits fell to £4.1m from £9.4m over the same period the previous year on revenues that fell to £26.5m from £31.3m.Among the deals Numis has been involved in are the floatation of the online betting exchange Betfair. Other floats have been postponed in recent months due to the market conditions."Ongoing uncertainty in economic and market conditions persists creating a challenging and competitive business environment," said chief executive Oliver Hemsley."However, we are encouraged by aspects of our first half performance."