Property group British Land reported continuing strong demand for its retail and office properties in spite of economic weakness as it posted a rise in profits and net asset value (NAV) in the year to 31 March.At £256m, underlying pre-tax profits were 9.9% higher than in the previous year. The value of the company's portfolio climbed by 6.9% to £9.6bn, which lifted NAV per share by 12.5% to 567p."While, as a nation, we have moved from 'Recession' to the 'Age of Austerity', consumers are still shopping and good businesses are looking to grow," said chairman Chris Gibson. "British Land has been well served by the quality, location and sustainability of its portfolio."Retail assets, such as the St Stephens shopping centre in Hull, account for 66% of British Land's portfolio, while London offices, including Broadgate in the City of London, account for 32%.The company said it is focused on retail assets that are "accessible and affordable" and that demand for offices remains strong."Therefore, while the economic recovery in the UK remains weak, we are optimistic about the prospects for the business and look to the future with confidence," it said.---RG