U.S. soybean futures were expected start Tuesday's day session higher, with strong demand, tight supplies and weakness in the U.S. dollar, buoying prices.

Analysts project soybeans to open 3 cents to 5 cents higher on the Chicago Board of Trade. In overnight trading, March soybeans, the most active contract, was up 5 cents at $14.18 a bushel.

Futures were expected to continue to find buyers in the midst of bullish fundamental outlooks, as consistent export demand in the face of precariously low projected soybean ending supplies serve as the catalyst to generate upward price movement.

Crop supplies have grown precariously tight on strong global demand and poor weather conditions in some parts of the world. Future's prices have surged since last summer with soybean contracts now trading at more than two-year highs.

The market also has an objective of pushing prices in an effort to sustain or increase U.S. acreage in 2011. Prices aren't likely to see a change in direction until there's a better sense of whether U.S. farmers can sow enough soybeans in 2011 to replenish depleted supplies.

Futures were seen garnering further support from the ongoing labor unrest in Argentina that is tying up loadings at Argentina ports.

"The port strike in Argentine is starting to raise additional concerns that the strike may not be an isolated issue and could drag out into key soy export season in coming months," according a Benson Quinn Commodities Inc. market note.

A weaker dollar is supportive to commodities as well, as most raw materials are dollar-denominated, making it less expensive for foreign buyers to import.

However, the uncertainty of Argentina production, with recent rains alleviating dryness issues is expected to limit advances. Meanwhile, Brazil is poised for record soybean production following favorable growing weather.

The Telvent DTN weather forecast said episodes of rain and thunderstorms continue to provide needed moisture for major corn and soybean areas in Argentina while hot weather is limited. "This is an improving weather pattern for crops," Telvent added.

Brazil and Argentina are the world's second- and third-largest producers of soybeans behind the U.S. and are counted on to relieve the strain on U.S. supplies amid strong global demand.

Nevertheless, strong China demand is seen buoying prices until South American harvest supplies are available for export, but fresh sales are expected to slow as the Asian nation, the world's leading soybean importer heads into a weeklong Lunar New Year holiday break on Wednesday.

U.S. Department of Agriculture announced Tuesday, private exporters reported the sale of 110,000 metric tons of soybeans to unknown destinations and 20,000 tons of soyoil to China. Both sales were for delivery in the 2010-11 marketing year.