(Adds further detail on Dingemans, evolution of GSK under new CEO)
By Ben Hirschler
LONDON, May 9 (Reuters) - GlaxoSmithKline Plc, Britain's biggest drugmaker, faces more top management change with Chief Financial Officer Simon Dingemans set to retire next year.
The former Goldman Sachs investment banker, who joined in 2011, will step down from the board in May 2019, the company said on Wednesday. As his departure is voluntary he will not receive any severance payment.
GSK said it planned to look both internally and externally to identify a successor.
Dingemans' departure provides a further opportunity for Chief Executive Emma Walmsley to stamp her imprint on the group as she tries to boost sales and improve productivity in the core pharmaceuticals division.
Walmsley, who took over in April 2017, has already appointed a new head of pharmaceuticals in Luke Miels and a new head of drug research in Hal Barron, as well as making Karenann Terrell head of digital operations, an area within Dingemans's orbit.
In his time at GSK, Dingemans has helped oversee two transformational deals with Novartis - the first, in 2015, involving a major swap of assets and the second, in March, in which GSK bought Novartis out of their consumer healthcare joint venture for $13 billion.
Prior to joining the drugmaker, Dingemans also helped as a Goldman adviser in establishing GSK's ViiV Healthcare joint venture in HIV medicine with Pfizer.
Dingemans said he believed he was leaving GSK at a time when it had established "strong foundations" to deliver improved financial performance.
The company has faced a difficult few years, marred by a lack of new blockbuster drugs emerging from its research labs, dwindling sales of its ageing lung drug Advair and a corruption scandal in China.
But Walmsley said earlier in 2018 she was increasingly confident the company would be able to drive sales and profit growth over the next few years, helped by newer products such as its successful new shingles vaccine Shingrix.
Still, even with a renewed sense of urgency about R&D productivity, GSK's transformation will take time, with its next batch of new medicines not ready to reach the market before 2020.
Meanwhile, big challenges loom in two key areas, with a new drug from Gilead Sciences threatening the HIV business and U.S. generic competition to Advair possible by mid-2018. (Additional reporting by Justin George Varghese in Bengaluru; Editing by Elaine Hardcastle and Susan Fenton)