Credit checking firm Experian boosted profits at its half-year point despite tough market conditions.Reported profit before tax in the six months to 30 September rose to $351m from $318m a year earlier.Benchmark pre-tax profit, which excludes exceptional items, rose 5% to $437m. Broker Charles Stanley had forecast underlying pre-tax profit of $425m.Revenue dipped to $1,874m from $2,017m, but was 1% higher at constant exchange rates, driven by a strong performance in Latin America. Year on year organic revenue growth was 1% for the group as a whole.Net debt at the end of September was $2,048m, down $62m over the six month period.The EBIT (earnings before interest and tax) margin improved to 24.0% from 23.2% six months earlier.‘In the second half, we continue to expect modest organic revenue growth and, for the year as a whole, remain on track to grow profits at constant currency and deliver strong free cash flow,’ said Don Robert, chief executive of Experian.The first interim dividend has been hiked by 4% to $0.07.