Land Securities Group's annual net asset value (NAV) rose 4.1 per cent to 959p compared to a year earlier as the property investment company signed new development lettings.Analysts at Investec had predicted NAV per share of 885p.Profit before tax for the year to end of March increased 3.4% to £533m from £515.7m in 2012 driven by demand for lettings in London.During the year the group achieved £31.7m of development lettings and £26.4m of investment lettings, 3.1% ahead of estimated rental value (ERV).Trinity Leeds shopping centre opened close to full occupancy, and 20 Fenchurch Street in London is now 56% pre-let or in solicitors' hands, a year ahead of schedule. The company also made progress on London developments including Victoria Circle, 62 Buckingham Gate, The Zig Zag Building, and Kings Gate.Robert Noel, who took over as Chief Executive at the start of the year, said: "Our development window remains open. A strong balance sheet combined with discipline in recycling capital allow us to take advantage of that window, as shown by our announcement today to commit, with our partner Canada Pension Plan Investment Board, to the £768m first phase of Victoria Circle, a mixed-use development in London's West End."The company recommended a dividend of 29.8p per share, a 2.8% increase on the prior year's 29p.Shares climbed 1.44% to 948p at 08:31 Wednesday.RD