National Portrait Gallery director Sandy Nairne has announced he is to step down in February after 12 years at the helm.

Nairne, who has helped increase gallery visitor numbers by more than a third since his appointment in November 2002, plans to pursue his writing and advisory work.

“It has been a great privilege to lead such a special institution as the National Portrait Gallery, and I am very proud of what we have achieved over the past decade,” he said.

“The fact that two million visitors now come each year to visit exhibitions, take part in activities or see displays of this amazing collection in London, as well as around the country or online, is testimony to the dedication of all who work at the gallery and those who support it in so many different ways. The Gallery is in very good shape and will go from strength to strength.”

Nairne was previously director of programmes at Tate, and before that worked at the Arts Council of Great Britain, the Institute of Contemporary Arts, and the Museum of Modern Art, Oxford (now Modern Art Oxford).

Amongst other commitments, he is currently chair of the Fabric Advisory Committee of St Paul’s Cathedral, and chair of the Maggie’s Art Group, which advises on art for the Maggie’s cancer care centres.