Pre-tax profit slumped to £8.4m last year from £110m previously while revenue rose 7% to £2.2bn.
More than 700 roles were shed in the jobs cull, which also saw Keller book an exceptional restructuring charge of £61.4m over the year. Most of the hit came from goodwill writedowns and impairments.
Underlying operating profit was down 11% to £97m.
Keller reported net debt at year end of £286m up from £230m. It now aims to offset restructuring costs with asset disposals this year.
The UK, representing only 3% of overall group revenue, experienced a generally hesitant commercial investment climate.
But Keller said major infrastructure projects like HS2, would see the market for geotechnical work pick up noticeably towards the end of 2019, extending well into 2020 and 2021.
Alain Michaelis, chief executive officer, said that Keller had taken decisive actions across the group in 2018.
This involved closing its heavy foundations business in Singapore and Malaysia; restructuring its Waterway business in Australia and downsizing its operations in Brazil and Africa in response to adverse market conditions.
He said: “The internal improvement measures, coupled with a stable market outlook, a healthy order book and Keller’s leading position in the industry, give us confidence in the outlook for 2019.”
A new group-wide business improvement programme saw Keller appoint a director of Lean to focus on improving productivity, reducing volatility and removing waste from its processes and products.