Oil prices slid below $50 a barrel on Thursday due to persistently high crude inventories in the United States and concerns of slowing global demand growth, while a strengthening dollar could spur further selling. U.S. crude fell 35 cents to $50.10 a barrel, after diving to a low of $49.85, extending a loss of $1.62 on Wednesday. Prices are about 14 percent below the record-high of $58.28 struck in early April. London's Brent crude oil shed 46 cents to $49.61 a barrel. "We saw a larger-than-expected rise in U.S. crude inventories overnight, which is the key to the big fall. There are also some concerns over demand whether it is as strong as what people are thinking," said Daniel Hynes, a Melbourne-based resources analyst at ANZ Institutional Banking. A flood of OPEC imports pushed crude oil stocks in the United States, the world's top energy consumer, to a six-year high of 329.7 million last week. The inventories rose by a surprising 2.7 million barrels and were 30.3 million barrels higher than year-ago levels, the U.S. Energy Information Administration (EIA) said. Sentiment was also dampened by remarks by the Paris-based International Energy Agency (IEA) that high fuel prices were slowing oil demand growth in key markets China, Europe and the U.S. China's demand growth slackened to 4.5 percent in the first quarter this year from 19.3 percent a year ago. The West's energy watchdog trimmed its annual China demand growth projection by 30,000 barrels per day (bpd) to 470,000 bpd. "Certainly, that would put more pressure on prices, particularly the downward forecast on Chinese demand. China has been the prime driver of global rise in consumption over the past year or so," Hynes said. First-quarter demand growth in the U.S. slowed to 250,000 bpd, or 1.2 percent, from 340,000 bpd, the IEA said. Despite the softer market, OPEC-member Indonesia does not want the cartel to cut crude production because global oil prices are still deemed high.