Shares in Corac slumped after the compressor technology specialist said the start of a field trial for a project to be conducted with the Italian oil and gas group Eni would be delayed until the second half of 2010 rather than the fourth quarter of 2009.The trial involves using Corac's compressor technology on a site in southern Italy. Corac said previously that it required many multidisciplinary contractors to be organised and permissions granted so could be subject to delay.'I am obviously disappointed that Corac is unable to start field trials in 2009 as planned, but pleased that the Company is now putting in place a revised plan to deliver to Eni,' said chief executive Phil Cartmell.Corac said it was in discussions with two other potential field trial partners to use its technology, one in the US and one in the Middle East.