* East coast wheat hit by lower-than-average protein levels -traders
* Tight supply of high-protein Aus wheat drives wider spreads
* Asian buyers may increasingly look to N.America
By Colin Packham
SYDNEY, Dec 19 (Reuters) - Wheat harvested recently across Australia's east contains less protein than average, traders and analysts said, tightening supplies of high-quality grain from the world's No. 2 exporter.
Asia's top buyers, who rely on Australia for the bulk of their milling wheat supplies, may be forced to import larger volumes of high-protein spring wheat from the United States and Canada, supporting global prices.
Lower-than-expected protein levels were found in wheat harvested in Queensland and northern and central New South Wales, the two states where the country's premier wheat is grown, earlier in the season, and traders said the trend has persisted with harvests near completion.
"The quality of the crop has been below average throughout the east coast," said Graydon Chong, a senior grains and oilseed analyst at Rabobank.
Fears over tight global wheat stocks have eased in recent days with improved crop weather forecast for U.S. winter wheat in the next few weeks and signs of increased demand for U.S. stocks.
That has supported Chicago Board of Trade March wheat futures, which have firmed in the last two days.
But spreads for high-quality Australian wheat have widened, reflecting the tightness of the premium grain, traders said.
"We have seen a widening of spreads between the high-protein wheat such as Australian Prime Hard wheat and Australia Standard White wheat, and that reflects the pressure in the market for high-protein wheat," Chong said.
Australia's 2012/13 wheat marketing year has already been hampered by unfavourable weather, leading to cuts in production forecasts, though concerns that dry weather would drive significant reductions in production levels earlier in the year failed to materialise.
Australia has trimmed its wheat production forecast in the current marketing year by 2.3 percent from its previous estimate to 22.03 million tonnes.
Reporting by Colin Packham; Editing by Joseph Radford