The Dutch company's British building arm, BAM Construct, reported a reduced turnover of £945.9m, compared to £1,037.2m in 2010.
Pre-tax profit shrank from £17.1m to £11.5m.
However, the firm has cash in the bank to the tune of £211.7m.
New clients in 2011 included Network Rail, for whom it is building the new national centre at Milton Keynes.
At BAM Nuttall, the group's civil engineering business, turnover increased to a record £809m from £694m the previous year.
But its pre-tax profit also decreased, from £15.7m to £14.1m.
The firm's order book stands at £966m, following contract awards from Crossrail and Olympic Park Legacy Company.
BAM PPP, the investment arm, posted reduced turnover of £55.7m (2011: £60.9m) and profit before tax of £3.1m (£3.9m).
Martin Rogers, who overseas the UK operations from Royal BAM's executive board, said: “The steady performance is the result of a heightened focus on prudently managing the difficulties inherent in the UK market. The companies have resisted the temptation to bid at unsustainable prices, have concentrated on maintaining standards and additional management and supervision of the supply chain.
“The UK companies have focussed on maintaining quality, making new strides in sustainability, and innovations such as Building Information Modelling (‘BIM’), in order to continue to provide a customer focussed service.”