Oil prices backed away from a three-week high of $52 a barrel on Tuesday as traders breathed easier after the long weekend and the U.S. dollar rose, but expectations of strong summer demand kept losses in check. U.S. light sweet crude for July delivery was down 13 cents at $51.72 a barrel in early Asian trade, having touched $52 a barrel last Friday, its highest since May 10. Traders pushed prices up 84 cents on Friday, guarding against any unexpected events over the three-day holiday that kept U.S. and London markets closed on Monday. Oil gained just over $5 a barrel last week after commercial oil inventories in the United States showed a surprise decline and as the dollar's rally against the euro appeared to stall. However, the dollar surged this week to another seven-month high versus the euro after France rejected the European Union constitution. Those gains attracted fresh flows of speculative hedge fund money, a major factor in the two-year energy market boom, and threaten to make dollar-denominated oil imports more costly for non-dollar economies, curtailing demand. Speculators increased their net short holdings in the New York Mercantile Exchange's (NYMEX) crude market in the week to May 24, betting prices would fall, regulators said on Friday. But prices rallied the next day on the unexpected fall in inventories, which analysts say should continue to be depleted by refiners striving to satisfy higher summer motor fuel usage. "The odds are there is probably going to be another fall in crude stocks, and that will tend to support prices a bit," said David Thurtell, Commodity Strategist at the Commonwealth Bank of Australia.