easyJet raised its annual profit guidance on Thursday on the back of strong demand in the second half.In a trading update ahead of its results for the year to the end of September 2013, the low-cost airline said it expects pre-tax profit of between £470m and £480m compared with the previous guidance of £450m to £480m. The European carrier anticipates a 6% rise in revenue per seat at constant currency for the three months to the end of September, driven by a robust performance in July and August. The group also predicts a 6% rise in revenue per seat at constant currency for the last half despite the effects of the political unrest in Egypt and the £25m adverse impact from the movement of Easter which fell on March 31st, a week earlier than in 2012.The airline estimates that at current fuel and exchange rates its unit fuel bill for the first six months of financial year 2014 will increase by £20m to £30m compared to the first half of this year.easyJet's unit fuel cost in the second half are pegged at £13m. More than a quarter of seats in the first half of fiscal year 2014 have been sold in line with the prior year."easyJet has delivered a strong performance in the last twelve months due to management action to generate value to our customers and maintain a tight control of costs combined with an unusually benign capacity environment," said Chief Executive Carolyn McCall. "easyJet's great network, friendly customer service, cost advantage and strong balance sheet means it will continue to be a structural winner in European short haul aviation and to deliver sustainable returns and growth for shareholders."Separately, the company announced that the number of passengers rose 4.8% to 5.7m in September compared to the same month a year ago. The load factor, the number of passengers to the number of seats available, increased by 1.2 percentage points to 89.7% last month.RD