Aggreko, provider of mobile generators, reported a 56% increase in interim pre-tax profit, upped its dividend 15% and said its outlook for the full year remains unchanged. Pre-tax profit for the six months to 30 June 2009 rose to £105.7m from £68.6m the year before. Revenue for the period increased by 23% to £499.8m.International Power Projects revenue increased by 40% and trading profit rose by 72%, in constant currency and excluding fuel, the group explained.It has secured a number of new contracts in Kenya, Saudi Arabia, Ethiopia and in Guadeloupe and said that new businesses in South Africa and India have made an encouraging start.However the group cautioned that while there has been more power on rent than a year ago, rates have been noticeably weaker."The outlook for 2009 is unchanged with profits in constant currency expected to be similar to 2008 despite tough H2 comparatives with Beijing Olympics and exceptional US storm revenues in 2008," Aggreko said in a company statement.Net debt was reduced by £77m in first half to £287m.The board has recommended the interim dividend be increased by 15% to 4.37p per share.