The UK construction industry shrank in August as new orders dropped at the fastest pace since April 2009, according to Markit Economics.

An index based on a survey of purchasing managers fell to 49 from 50.9 in July, Markit and the Chartered Institute of Purchasing and Supply said in a statement on Markit’s website today. The median estimate in a Bloomberg News survey of 12 economists was for a reading of 50, the dividing line between growth and contraction.

“UK construction firms are suffering a prolonged downturn in new work and there is little evidence to suggest an imminent rebound in output levels,” Tim Moore, senior economist at Markit, said in the statement. “A construction decline for 2012 overall is statistically baked in the cake.”