Ithaca Energy's shares declined after the company said its anticipates full-year production will be at the lower end of annual guidance of 14,000 to 16,000 barrels of oil equivalent per day (boepd). The group based its 2013 expectations on production in the first half and the challenges ahead in second half. In the first six months the company achieved average net export production in of 14,300 boepd with 95% oil.Production from the Athena field was partially reduced during the second quarter as one of the four producing wells, the "P2" well, was temporarily shut-in. A repair was successfully completed as planned in early July 2013 and the well was brought back online. The key risks to production in the second half relate to completion of works on certain of the company's non-operated assets and the results of an ongoing evaluation on one of the Athena wells. Drilling on the Stella field started in June with the first development well progressing as planned.Pre-tax profit for the first half came to $71.4m compared to the previous year's $35.5m. Net earnings climbed to $55.7m from $43.2m. Cashflow from ongoing operations was $187.4m.In April, the group completed the acquisition of Valiant which led to restructuring costs in the second quarter.Iain McKendrick, Chief Executive Officer, said: "In the first half of the year we have both doubled production and operating cashflow and importantly diversified our producing asset base to 11 fields."The Greater Stella Area development is moving forward rapidly and with the integration of the Valiant acquisition now completed, including restructuring of the UK exploration portfolio, we look forward to an active second half of the year."Shares fell 1.68% to 117p at 11:13 on Tuesday.RD