Merck, one of the world's oldest chemical-pharmaceutical companies, is in the final stages of concluding a multi-million US dollar investment deal on the mainland. Horst Witt, Merck's chief China representative, said he expected the deal, representing the firm's first big investment in the country, to be finalised within weeks. The deal would enable the German company to buy a majority stake in a mainland pharmaceutical factory that would then be upgraded to produce Merck's beta-block product and other cardiovascular products. Mr Witt declined to give more details about the investment, citing continuing negotiations. The deal is part of Merck's plan to increase its presence in the pharmaceutical market, which has an estimated annual growth rate of between 12 and 13 per cent. Merck, which established its first mainland office in 1994, sold about $11.63 million worth of pharmaceutical products in the mainland last year. Mr Witt said he expected sales to increase tenfold within the next five years. He said having a manufacturing presence on the mainland would enable Merck to shorten the new product-registration process and make its products more accessible to people on the government's free medical-care coverage. The authorities have encouraged doctors to give priority to locally manufactured products when prescribing medicine to patients. Merck, which traces its roots to 1668, has annual revenues of more than $36.44 billion and owns production facilities in 26 countries.