The aim would be to sell works by living artists, such as David Hockney or Howard Hodgkin, and buy others by the same artists to improve the range and quality of pieces the gallery holds.
Many people in the art world lament the lack of money available for acquisitions, and Tate Director Nicholas Serota has complained about how the gallery is offered works nearly every day it cannot even contemplate buying.
There are strict rules on what Britain's national museums and galleries are allowed to do with their works. They are allowed to sell or dispose of works -- what is known as de-accessioning -- under the 1992 Museums and Galleries Act if an item is "unsuitable for retention."
The Tate believes that selling works to upgrade the collection is permissible under these rules, although that interpretation could be open to challenges, the newspaper said.