Shares in Galen Holdings, the Northern Ireland pharmaceutical firm, jumped by 9.1 per cent to an all-time high of 641p sterling (€10.05), following an announcement of a £39.7 million sterling investment which will increase employment by 300.

The group's market capitalisation rose by £65 million to £778 million.

This latest investment is on top of the £21.5 million expansion announced in February, creating 125 new jobs.

Galen already employs 800 at its two Northern Ireland plants and 200 at its US facilities in Philadelphia, Princetown (New Jersey) and San Francisco. The new investment, which is projected to increase sales by 77 per cent, will be in an innovative drug delivery system. The new jobs will be created in its Craigavon, Co Armagh and Larne, Co Antrim plants over the next three years.

Most of the jobs will be in Craigavon, including 51 in the SynGal division which provides pharmaceutical synthesis and chemical technology services. There will be 53 new jobs at Larne where the company intends to manufacture its new intravaginal ring drug delivery system for the treatment of symptoms associated with the menopause. Dr Allen McClay, Galen's chairman, said the investment would contribute to the projected 77 per cent increase in turnover "by broadening our production and analytical capacity and strengthening our portfolio of prescription medicines and clinical services".

The group, he added, was "implementing a growth strategy designed to drive forward all our divisions and to consolidate our international reputation for excellence in products and services. The strategy will position the company to respond faster and more flexibly to the exciting business opportunities, which we have identified in the continuing growth of the global pharmaceutical industry, particularly in new drugs and delivery systems".

The North's Industrial Development Board has offered selective financial assistance of £10.4 million towards the cost of the investment.

Galen's latest results showed a 26 per cent rise in pre-tax profit to £9.5 million and a 29 per cent growth in sales to £31 million in the six months to March 31st, 1999. The results for the full year, to end of September, are due out tomorrow. Brokers have projected a rise in pre-tax profit from £14.7 million to around £19 million.