LONDON (Dow Jones)--Shipping services group Clarkson PLC (CKN.LN) Wednesday said first-half trading is ahead of its expectations, reflecting an improvement in shipping markets and foreign exchange benefits. Clarkson didn't give details of its internal forecasts but analysts expect the company to post a pretax profit of GBP24.7 million on revenue of GBP184 million for 2010 according to FactSet. -By Rachael Gormley, Dow Jones Newswires; 44-20-7842-9308; [email protected] (END) Dow Jones Newswires June 30, 2010 03:14 ET (07:14 GMT)