The fall was largely down to the property arm, which suffered an £11m loss after making provisions on several regional developments. Total UK turnover remained flat at £1.73bn.
Building arm Bam Construct managed to improve its margins on reduced turnover, down 7%.
The firm said: “The economic conditions in the UK construction market are starting to be hit by the consequences of the spending cuts.
“Major regional differences in UK construction activity are now very apparent.”
In contracts, Bam Nuttall revenues rose 7% but profitability was below last year’s performance.
Nico de Vries, chief operating officer, said: “We have a very strong order book in the UK. We see Bam Nuttall as a very strong company in a very competitive market.”
Bam said property activities were at a low level in 2010 and the cautious recovery only in prime locations.
Although BAM Properties started development work on two new property projects in Glasgow and London during the second half of 2010, additional provisions of over £5m were taken on several regional projects resulting in a £11m loss.
The Property group’s unsold and unlet stock of commercial property in the UK amounted to approximately 22,700 sq m of space at year-end 2010.