Mona Barthel of Germany, winner of this year's GDF Suez tennis tournament.

GDF Suez has announced the acquisition of UK firm Balfour Beatty's facilities management business, WorkPlace, to boost its energy services and facilities operations in the UK.

GDF claims the acquisition of Workplace will generate annual revenues of approximately £800m ($1.2bn, 929m), but the company is yet to reveal the financial details of the deal.

The firm said the enterprise value of the business on a debt and cash-free basis is £190m. The cash, however, will be reduced by pension liabilities and any debt transferring with the business. The company also added that this is subject to certain adjustments based on completion accounts.

"This acquisition will consolidate the Group's significant European position in energy and facilities services and will also create a strong position for GDF SUEZ in the UK," Jerome Tolot, chief executive officer of GDF Suez Energy Services, said in a statement.

"It is fully in line with the Group's strategy to provide innovative and energy efficient solutions for customers across all sectors of the built environment, assisting them with the transition to a low carbon economy and in the creation of the cities of tomorrow".

The WorkPlace facilities management unit, which employs about 9,000 people, generated £481m of revenue last year with operating profit of £21m.

WorkPlace provides various services to British people including hospitals, schools and local government establishments, complementing GDF Suez's Cofely business, which providesf energy and technical services to the private sector.

GDF Suez energy services, which is the UK's largest provider of district energy, currently employs about 2,200 people in the Britain. It provides services to 13,000 customer sites in commercial, industrial and public sectors.

The deal is expected to complete in the fourth quarter of 2013.