GlaxoSmithKline (GSK) has tapped Englishman Andrew Witty to succeed Jean Pierre Garnier as CEO in May.

At age 43, Witty will become the youngest–ever leader of Europe’s largest drug maker at a time when the company is seeking to reinvigorate its sales growth.

Witty has worked for the UK-based GSK in the US, Asia and Africa and became president of European operations in 2003.

Witty joined GSK in 1985 in the UK where he held positions as director of pharmacy and distribution and international product manager.

Outside the UK, he was director for south and east Africa and marketing manager for GSK’s US unit before moving to Singapore as an Asian SVP.

Garnier, who turns 60 at the end of October, joined SmithKline Beecham in 1990 as president of its North American pharmaceuticals division. He was named CEO in 2000.