Property group Hammerson reported a 7% rise in half year profit as its markets continued to recover from the recession over the first half of 2010, but cautioned that the outlook remains uncertain.Adjusted pre-tax profit rose to £70.2m in the six months ended 30 June from £65.6m last time, thanks to lower finance costs, new lettings and rent reviews.Net rental income dropped to £140m from £156.4m, due to property disposals in 2009, but like-for-like net rental income was up 5%. The board has declared an interim dividend of 7.15 pence per share, which compares with 6.95 pence for the first half of 2009. Chairman John Nelson said: "The underlying quality of our portfolio has been demonstrated in our results, with lower vacancy and growing income in a challenging environment." "Over the period we have executed a number of transactions which will improve the future growth prospects of our business whilst releasing capital for potential reinvestment. We have advanced our valuable development pipeline in the UK and France which will provide a basis for additional future growth."