Building giant BGC slumped to a $67.6 million net loss in the year to June 2017 from a $32 million profit a year earlier, newly filed figures with the corporate regulator show.

BGC, which ranked as Australia's sixth-largest privately owned company last year, swung into loss as expenses jumped by almost $100 million to $1.96 billion and revenue dropped by $70 million to $1.9 billion, the figures show.