Nov 22 (Reuters) - Severn Trent retained its annual financial forecast on Wednesday, even as the British water utility posted an about 3% fall in half-yearly profit, mainly hurt by higher energy and chemical prices.

British water utilities have been under government and public scrutiny for paying executives bonuses and shareholders dividends while industry environmental standards remain subpar.

Severn Trent, which has avoided some of the worst fallout from a recent Ofwat review, said it was on track to outperform a measure used by regulators to monitor the performance of utilities.

The FTSE 100 company, which was formed in 1974 and provides water services in England and Wales, said its profit before interest and taxes came in at 255.1 million pounds ($317.9 million) for the six months ended Sept. 30, compared with 261.7 million pounds a year earlier.

In September, Severn Trent announced plans to invest 12.9 billion pounds and said it would raise 1 billion pounds to help finance the investment as water companies in the UK aim to tackle water quality, leakage and pollution issues. ($1 = 0.8025 pounds) (Reporting by Prerna Bedi and Aby Jose Koilparambil in Bengaluru; Editing by Subhranshu Sahu)