Results were hit by £2.5m in provisions for legacy contract claims and the £3.2m cost of closing its North Associates operation.
WYG also blamed “losses in our real estate business, high rates of staff turnover in two key businesses areas, delays in major projects, and revised expectations of a small number of engineering projects.”
But chief executive officer Douglas McCormick is confident things will pick up this year.
He said: “Many of the major projects in both of our principal business streams that were delayed in 2017 are now being delivered and our strong order book underpins a significant proportion of FY19’s projected earnings.
“We have a clear strategy in place, a reshaped leadership team and a strong wider group with deep expertise in our chosen markets.
“There is plenty of opportunity to build on this robust platform and I believe we are taking the right steps to return to growth in profitability.”