Surveillance systems firm Petards took a knock after it said some new contracts would not contribute as much to 2012 revenues it had hoped.

The firm also said other contracts it had been expecting to receive in the third quarter now seemed likely to be delayed into 2013.

As a result the firm expects revenues in the second half year to be slightly ahead of those for the first half year and the operating performance to be similar to that achieved in 2011.

Revenues dropped from £5.2m to £4.7m in the six months to the end of June.

However, gross margin were up slightly to 41.3% and profit before tax jumped to £22,000, from £5,000 the previous year.

Basic and diluted earnings per share came in at 0.35p, up from 0.08p the year before.

Shares closed down 8.2% on Thursday.

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