(ShareCast News) - Geotechnical contractor Keller Group posted its results for the six months to 30 June on Monday, with record first half revenue of £850m, up 12%, but guided markets towards the lower end of the Board´s range of expectations.The FTSE 250 firm had an operating profit before exceptional items down 6% to £35.6m, or down 10% at constant currencies, with underlying cash generated from operations up 125% to £41.9m.Earnings per share were down 12% to 27.4p, or down 16% at constant currencies.It reported strong performances from North America, and Europe, Middle East and Africa, but had a disappointing result from Asia Pacific.It said it was on track to deliver its medium-term objectives, with the order book to be executed in next 12 months up 10% on the same time last year.However, "overall we expect the full year Group results to be at the lower end of the Board's expectations," the company cautioned.Keller's board declared an interim dividend increase of 5% to 9.25p per share"We have seen an encouraging start to the year in North America and EMEA, our two largest divisions," said Keller chief executive Alain Michaelis."APAC made a loss in the period, due to market conditions and project delays, but we expect a return to profitability in the second half of the year."Overall, the group continues to make good progress against our medium-term objectives, building on our strong market positions and favourable market trends," Michaelis explained.