Derwent London has put its faith in the capital's real estate market with the purchase of two properties in the West End.The property group is buying an office building in Victoria for £45m and one on Tottenham Court Road for £31m. Derwent announced the acquisitions as it reported an increase in its net asset value to £2.4bn on 31 December, up 16% from a year earlier."Derwent London's strong performance in 2010 has continued into 2011," said chief executive John Burns. "Our distinctive brand of contemporary mid-market office space remains attractive and we are accelerating schemes to deliver new space into a supply-constrained market."Derwent says that, while times are tough in Britain in the aftermath of the recession "the London economy has shown great resilience and demand remains strong from both UK and international purchasers for central London property."