GALEN Holdings, the drug company which is one of Northern Ireland's biggest manufacturing employers, will be worth Pounds 181.9 million when it floats on the stock market next week.

However, even after the company comes to the market, most of it will still be in the bands of its three main bosses, who will become multi- millionaires. The opening price will be 150p, which means that founder, Mr Allen McClay's 34.7 per cent stake will be worth about Pounds 63 million sterling.

Chief executive, Dr John King has a 22.2 per cent stake worth Pounds 40.4 million, and finance director, Mr Geoffrey Elliott has a 7.2 per cent stake worth Pounds 13.1 million.

Their original holdings are being cut as a result of the float. Mr McClay originally held 47 per cent of the company, while Dr King had 29 per cent and Mr Elliott 10 per cent.

The float, due for next Thursday, will raise Pounds 30 million to finance the expansion of the Craigavon, Co Armagh-based firm, which currently employs 600 people.

Last month Mr McClay, who founded Galen in 1968 after leaving Glaxo, announced he was donating Pounds 17 million worth of his shares to the company's staff and Queens University, Belfast. The intention was, he said, to benefit employees past and present and the chemistry and pharmacy schools at the university.

A trust for Gal en staff received shares worth Pounds 7.5 million and Queens University gets a stake worth Pounds 9 million. Galen's staff will also be at the front of the queue if they want to buy more shares at 150p as 1.2 per cent of the shares being issued have been set aside for them.

Dr King said that directors were "delighted" by the response to the flotation. "The money raised will provide us with a more flexible capital base to allow us to pursue our strategy to grow and invest in our businesses," he said.

Although most of the company will remain in the hands of the three directors after the float, they believe it will "raise the status" of Galen on the international scene.

The bulk of the Pounds 30 million will be used to fund the expansion of Galen's Clinical Trials Supplies business, which packages and distributes new drugs used in patient trials. The company's other main activities include making prescription analgesics, or painkillers, and medicines for stomach, intestinal and respiratory diseases.

Galen made a profit of Pounds 7.2 million in the year to the end of September 1996 on sales of Pounds 31 million.