Shares of recruitment services firm Work Group plummeted after it said half year gross profit declined 4% from the same period last year as challenging conditions for recruitment services continues.The aim quoted company said net fee income, or gross profit, for the six months ended June 30 fell to £6.2m after it experienced a particularly slow first quarter. Work Group made a small operating profit for the period, despite tough conditions, and remains debt-free with net cash in excess of £0.5m. Shares in the group plunged nearly 17% following the trading update.Work Group will announce its results for the period on 18 September 2012. CJ