Pub group and real ale brewer Marston's reported a 21% drop in half-year pre-tax profit but said it is encouraged by the modest improvement in trading since mid-February.Profit before tax and exceptional items fell to £27.7m in the 26 weeks ended 4 April, in line with expectations, compared with £35m last time. Turnover of £307.5m was 2.8% below last year.The interim dividend is unchanged at 4.80p.Total like-for-like sales for the 13 weeks to 16 May were 1.0% above last year including food sales up by 5.6%. Trends in Marston's Pub Company and in Marston's Beer Company are consistent with those reported for the half-year."We've been encouraged that over the last 13 weeks or so, we have seen an improvement in our trading. I think it remains fragile. But we are cautiously optimistic," said chief executive Ralph Findlay."We remain well positioned to benefit from any sustained up-turn in the trading environment and to exploit opportunities presented by the changing demands of customers, including increased tourism in the UK. Costs remain firmly under control and cash generation strong. ?We are confident of meeting our expectations for the year as a whole," he added.