More than 800 workers at a giant Bradford chemicals site are waiting to see what the future holds after the authorities gave the go-ahead for a take-over of the company’s owners.

Swiss-based chemicals firm Ciba is set to become part of the world’s largest chemicals company BASF later this week.

Merger authorities in the United States and China, along with the European Commission, approved the deal which is due to complete on Thursday.

BASF, based in Ludwigshafen, Germany, agreed to pay 50 Swiss francs a share for Ciba, and will hold around 95.8 per cent of the shares in the company.

Dr Mike McFarlane, site director, said it was too early to say what impact the BASF take-over would have on the Bradford plant.

A BASF spokesman said once the acquisition was completed “a period of discovery” would begin to review the Ciba business in detail and see how Bradford would operate under its new ownership.

It is likely to be the second half of the year before details were known and decisions made.

The Bradford plant, which was Allied Colloids until Ciba bought it in 1998, is the largest in the Swiss-based chemicals group Ciba has invested an average of £6m a year in developing and modernising the 65 -acre site.

Around 60 per cent of products from Bradford are exported around the world, with China and India offering substantial growth potential. The Bradford operation specialises in chemicals for the paper industry and water treatment and purification.

BASF has approximately 97,000 employees and last year achieved sales of more than £52 billion Its shares are traded on the stock exchanges in Frankfurt, London and Zurich.

In the UK the group operates around ten sites. mainly in the North West, Midlands and South East as well as Scotland and Ireland. BASF opened it first UK sales offices in London and Manchester in 1880.