U.S. wheat futures are expected to start higher Tuesday on weakness in the dollar and hopes for a near-term resolution to Greece's debt crisis.

Traders and analysts predict soft red winter wheat for September delivery, the most actively traded contract, will start up 8 cents to 10 cents a bushel at the Chicago Board of Trade. In overnight electronic trading, the contract rose 8 3/4 cents, or 1.3%, to $7.04 1/2 a bushel.

Weakness in the dollar and optimism about Greece are supportive to prices as they temporarily ease fears about reduced demand for commodities, including grains, traders said. A soft dollar makes U.S. grains more attractive to foreign buyers, while an improving outlook for Greece reduces concerns a slowing global economy would cut into consumption.

"Much of the focus so far this week is on a falling dollar and developments in Greece," said INTL FCStone, a commodities brokerage firm.

Traders are watching factors that can impact demand for commodities after concerns about sluggish demand helped push wheat prices to a 7 1/2-month low Monday. Prices have pulled back 25% since reaching a 2 1/2-year high in February on an increase in export sales.

Yet, ongoing harvests in the Northern Hemisphere are hanging over prices, as farmers are bringing in fresh supplies from the fields. The U.S. winter-wheat harvest was 31% complete as of Sunday, above the five-year average of 22% for that time of year, according to federal data issued Monday.

Futures prices should struggle to advance as the harvest continues to progress, said Rich Feltes, vice president of research for RJ O'Brien in Chicago. The "bulk of winter wheat harvest hedge pressure still lies ahead, with over two-thirds of 2011 U.S. wheat still in the field," he noted.

In China, more than 90% of winter wheat had been harvested as of Monday and a rise in summer grain output is an "inevitable outcome," according to the Ministry of Agriculture. Farmers in the Black Sea region also are cutting wheat, with 35,000 metric tons harvested in Ukraine as of Monday, the government said.