American giant Tetra Tech has completed the £43 million acquisition of professional services firm WYG.

Californian-based Tetra Tech UK Holdings Limited confirmed on Tuesday that its offer to acquire all of the outstanding shares of WYG plc, first revealed in May, had been completed.

Trading in WYG shares on the London Stock Exchange (LSE) has been suspended with all of WYG’s 78,941,048 shares now owned by Tetra Tech, which provides consulting and management services to industries including water, infrastructure and energy.

WYG, which provides global programme, project management and technical consultancy, has an office at Lakeland Business Park in Cockermouth, from where it delivers major contracts for clients including Sellafield Limited and Cumbria County Council.

Tetra Tech said the acquisition of WYG, which employs 1,600 staff across the UK and Europe, would expand its geographic presence and strengthen its position in the global marketplace. Tetra Tech already employs more than 17,000 people in 400 offices around the world, including six in the UK.

Its chairman and chief executive, Dan Batrack, said: “The addition of WYG advances our strategy to be the premier global high-end consulting, engineering, and programme management firm.

“WYG’s expertise in infrastructure and program management, as well as water and environmental services, enables us to deliver innovative solutions to support the UK’s infrastructure needs. Together, we will provide an expanded scope of services to our customers and offer our combined staff even greater professional opportunities.”

WYG first revealed the deal, understood to be worth around £43.4m, in a statement to the LSE in May

Its directors described the price as “fair and reasonable”, with each WYG shareholder set to receive 55 pence in cash per share.

Non-executive chairman Jeremy Beeton said the Tetra Tech takeover would help to strengthen its financial performance and proposition to clients.

WYG issued a profit warning in February this year, saying Brexit fuelled “cautious business sentiment and political uncertainty” was delaying investment decisions and impacting on its consultancy business in the UK, in which its Cockermouth office plays a key role.

Its balance sheet also took a £3m hit last year due to the closure of Carlisle-based North Associates – a property consultancy which it bought in a deal worth up to £5m in October 2015.

However, the company was recently buoyed by the award of a multi-million contract to its Nuclear Decommissioning Ltd (NDL) joint venture – which also includes Shepley Engineers Ltd, REACT Engineering and James Fisher Nuclear Ltd – to support the ongoing decommissioning of the Dounreay nuclear site in Scotland.

NDL will provide multidisciplinary services ranging from civil and structural engineering to design, architecture and project management, to support the clean-up and demolition of Britain’s former centre of fast reactor research and development.