* Chicago soybean add to Friday's strong gains

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

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

(New throughout, updates prices, market activity and comments; new byline, changes dateline HAMBURG/SINGAPORE)

CHICAGO, July 3 (Reuters) - Chicago Board of Trade (CBOT) soybean futures on Monday rallied more following a shockingly low plantings estimate from the U.S. Department of Agriculture (USDA) on Friday - news that sent the November new-crop contract surging more than $1.00 a bushel since the report's release.

Corn firmed at the start of this holiday-shortened week on a technical bounce and bargain-buying, as recent lower prices appeared to be luring buyers, traders said.

Several hefty import tenders were issued on Monday by buyers in South Korea and a large private purchase reported over the weekend.

Still, corn futures remained under pressure from a larger-than-expected U.S. corn plantings figure and smaller-than-expected June 1 corn stocks released on Friday by the USDA.

U.S. markets, including the CBOT, will be closed on Tuesday for the Fourth of July holiday.

Chicago Board of Trade most-active soybeans was up 21 cents at $13.64-1/4 a bushel at 1454 GMT. The session high was their highest since June 15 at $13.91-3/4 a bushel.

CBOT soybean, soymeal and soyoil futures were trading with expanded limits for Monday's session, after CBOT soyoil futures closed up their normal daily limit on Friday.

Corn was up 1/2-cent at $4.95-1/4 a bushel, after hitting 2-1/2 year lows on Friday and earlier on Monday. Wheat followed corn, ticking up 1/4-cent at $6.51-1/4 a bushel.

The department cut its estimate of U.S. 2023 soybean plantings to 83.5 million acres, down 4 million acres from its March 31 forecast and below a range of trade estimates.

"If USDA's estimate is accurate, the margin of error for U.S. soybean yields shrinks significantly and places even more importance on a shift in the weather pattern for the Midwest in the near future," StoneX chief commodities economist Arlan Suderman wrote in a client note. (Additional reporting by Michael Hogan in Hamburg and Naveen Thukral in Singapore; Editing by Rashmi Aich, David Evans and David Gregorio)