Child With A Dove, painted in 1901, was sold privately by Christie's earlier this year on behalf of the Aberconway family in Wales, to an undisclosed overseas buyer. It is believed the price was in the region of £50m.
The export bar will last until December, to see if the painting can be kept in the UK. It had been exhibited at the National Gallery from 1974 to 2010 and is now on show at the National Galleries of Scotland.
