United Utilities is still trading "slightly" ahead of management expectations, keeping the water utility on track for a "solid" underlying full-year result.Regulated revenue continued the positive trends seen during the first half but, as previously flagged, will be a "little lower" than the first six months due to seasonality.Total regulatory capital expenditure is expected to top £600m."As expected, regulated underlying operating profit is therefore anticipated to be somewhat lower in the second half of 2010/11, compared with the first half, although the full year position represents a healthy financial performance in light of the impact of the price review," it said.Additional costs linked to harsh winter weather were "not significant", though meeting 2010/11 regulatory leakage targets "extremely challenging".Full year results are out on 26 May.