LONDON (AP) — GlaxoSmithKline is investing some 275 million pounds ($360 million) into three plants in Britain, sweeping aside concerns about growth following the country's decision to leave the European Union.

The pharmaceutical giant's chief executive Andrew Witty said Tuesday that the Britain's "competitive corporate tax system" and skilled workforce influenced the decision to invest in the manufacturing of new respiratory and large molecule biological medicines.

Witty was among dozens of business leaders who had argued that Britain should remain in the 28-nation single market of some 500 million.

Britain's government describes the decision as a vote of confidence in the country and its workforce.

The investment will go to Durham and Hertfordshire in England and to Montrose in Scotland. The company has nine sites in the U.K., employing 6,000 people.