Tetra Tech has offered WYG shareholders 55 pence per share, which is more than three times the 16 pence that they were worth last week.
The offer values WYG at £43.4m
The board of WYG is recommending that shareholders accept the offer and 72.5% of the shareholding has already indicated that it will vote in support of the takeover.
WYG, previously called White Young Green, made a pre-tax loss of £5.3m in the year to 31st March 2018 on revenue of £154m. It has 1,600 employees operating out of more than 50 locations around the world.
WYG chairman Jeremy Beeton said: "The WYG board and I unanimously recommend the offer from Tetra Tech. Becoming part of the Tetra Tech Group enables benefits of scale and access to expertise across highly complementary geographies and client relationships, and brings operational infrastructure and financial strength to support WYG's long term growth ambitions. We provide Tetra Tech with a strong platform for investing in growth in the UK and Europe. We believe the combination of our two companies will provide greater opportunities for our people and clients, as well as offering certainty of immediate value to our shareholders at a considerable premium to the prevailing share price."
Tetra Tech Inc chairman and CEO Dan Batrack said: "WYG advances our strategy to add firms that support our position as the premier global high-end consulting, engineering, and program 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 be able to provide an expanded scope of services to our customers and offer our combined staff even greater professional opportunities."
Tetra Tech has 18,000 employees around the world and already has six offices in the UK: in Swindon, Harrogate, Manchester, Reading and two in London. Last year it generated revenue of close to US $3bn.