* Chicago soybean jump 3%, add to Friday's strong gains

* Lower-than-expected U.S. planting, tightening supplies support

* Corn rises from 2-1/2 year low; wheat up

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HAMBURG/SINGAPORE, July 3 (Reuters) - Chicago soybean futures rose again on Monday, rising around 3% as smaller U.S. plantings and inventories raised concerns over supplies.

Corn firmed after dropping to a two-and-half-year lows on signs lower prices were stimulating more import demand, especially in Asia. Wheat followed corn up.

"The markets are still amazed by the sharp cut in estimates of the U.S. planted area made on Friday," one European trader said. Chicago Board of Trade most-active soybeans rose 3.1% to $13.85-3/4 a bushel at 1044 GMT, after earlier on Monday hitting their highest since June 15 at $13.91-3/4 a bushel.

Corn rose 1.6% to $502-3/4 a bushel, after hitting 2-1/2 year lows on Friday and earlier on Monday. Wheat rose 0.1% to $6.52-1/4 a bushel.

Soybeans rose over 6% on Friday after the U.S. Department of Agriculture (USDA) said U.S. farmers planted 83.5 million acres of soy, down 4 million acres from its March forecast and below the lowest in a range of analyst estimates.

For corn, the USDA's plantings estimate of 94.01 million acres was up over 2 million acres from its March forecast and topped of analysts' estimates.

There were signs low prices were stimulating more corn demand, with hefty import tenders issued on Monday by buyers in South Korea and a large private purchase reported over the weekend.

Traders eyed news that efforts are being made to extend the agreement for a safe shipping channel for Ukrainian grains which expires in mid-July.

The European Union is considering a proposal for the Russian Agricultural Bank to set up a subsidiary to reconnect to the global financial network as a sop to Moscow, the Financial Times said.

With the bank under sanctions, the move aims to safeguard the Black Sea grain deal allowing Ukraine to export food to global markets, the newspaper said. (Reporting by Michael Hogan in Hamburg and Naveen Thukral in Singapore; Editing by Rashmi Aich and David Evans)