GlaxoSmithKline CEO Andrew Witty to leave drugmaker in March 2017

Witty has lead the company through several drug patent expiries and helped put it on track for earnings growth this year

Witty has struggled to raise the share price of the British drugmaker since he became CEO in 2008 (Getty)

The CEO of massive pharmaceutical company GlaxoSmithKline is stepping down in March 2017, capping a 31-year career there.

Witty has struggled to raise the share price of the British drugmaker since he became CEO in 2008 as he has lead it through a series of changes including a focus on consumer health products from headache pills to toothpaste.

A bribery scandal in China that ended in a a record 3 billion yuan ($463 million) fine also took its toll.

He counts among his successes getting through several drug patent expiries without resorting to acquisitions, and helping to put GSK on track for earnings growth this year.

His departure - though not a surprise - comes at a time of debate over the direction of GSK and investors may fear a period of limbo before a new CEO comes on board.

Some minority shareholders have called from a breakup of the group, arguing that pharmaceuticals and consumer health units would do better as standalone businesses.

Witty has argued against the spin-off, at least in the short term.

GSK has said it will consider both internal and external candidates for the new CEO role. Internatl candidates could include GSK's global pharmaceuticals head Abbas Hussain, leader of the consumer division Emma Walmsley and manufacturing head Roger Connor, as well as finance chief Simon Dingemans, a former Goldman Sachs banker.

GSK could also try to snare a leader from a rival drugmaker.

Additional reporting by Reuters.