GLA Land and Property (GLAP) is a subsidiary company of the Greater London Authority. It was formed on 1 April 2012 as a replacement for the London Development Agency (LDA) as an arms length corporate body to take on the assets of the LDA and other agencies, under the direction of the Mayor of London. It is one of the largest public sector landowners in London and its primary aims are to create jobs and housing. GLAP is headquartered in Windsor House, Westminster in the offices used by Transport for London.
More information on the Wikipedia page [1]. The Gov.uk page is here.