barrel fall in U.S. heating oil stocks, helping to sustain a rally on U.S. sweet crude futures to the highest levels since late April and marking an 18 percent rally from a low of $46.20 touched on May 20. Supplies of heating oil and other distillates are under pressure from increased demand from U.S. truckers, European motorists and Chinese power generators. Chinese officials have warned of a greater-than-expected summer power shortage, which could lead to higher demand for diesel for use in small generators. For further guidance on the adequacy of supplies, the market is awaiting the next set of U.S. inventory data to be released on Wednesday. Analysts expect the report to show another small increase in crude stockpiles, which have already grown to near 6-year highs due to strong imports.