But the megaproject's current chances of successful delivery was rated "unachievable" by the government's Infrastructure and
Projects Authority in its recent annual review.
Canada-based SNC Lavalin Group, the parent of Atkins, said the sale when completed will further speed the corporate transition to engineering and project management.
A 35-person Spanish technology developer joins European competition in the rapidly emerging global market for floating offshore wind energy turbine platforms.
Cost projections have run between $8 billion and $16 billion for the project to renovate the 1,100-room Victorian-era complex by the River Thames in London.