* Most-active CBOT corn futures near two-week high

* CBOT corn, soy bounce from three-year lows Monday

* Ample global corn supplies limit market gains

CHICAGO, Feb 27 (Reuters) - Chicago Board of Trade corn and soybean futures rose for a second consecutive session on Tuesday to recover from their lowest levels in more than three years.

Bargain buyers stepped in to the markets as low prices increased some demand from end users, traders said. Technical buying and short covering helped fuel the gains, they said, with speculators holding large short positions or bets that prices will fall.

Ample global corn supplies are expected to limit advances, though, analysts said. The U.S. also faces intensified competition for grain and soy export sales on the global market.

"It's very much a crowded, negative short position, particularly on corn," said Don Roose, president of brokerage U.S. Commodities "It's a little bit of evening up."

Most-active corn futures were up 3 cents at $4.24-1/2 a bushel by 11:25 a.m. CST (1725 GMT) and reached the highest price since Feb. 14. Soybeans advanced 1-3/4 cents to $11.47 a bushel, while wheat jumped 8-3/4 cents to $5.83-1/2 a bushel at the CBOT.

Traders have been adjusting positions before first notice day for CBOT March futures on Thursday.

Market participants were also watching for signs that prices are bottoming out, after the front-month corn contract on Monday bounced from a fall below $4 per bushel to its lowest level since November 2020.

"If you can get a 3-4 day rally out of it, then it's more convincing that's the low," Roose said.

In global demand, exporters sold 123,000 metric tons of U.S. soybeans to unknown destinations, the U.S. Department of Agriculture said. Still, the United States faces stiff competition from Brazil for export sales to China, the world's biggest soy importer.

Chinese importers are believed to have purchased a substantial volume of animal feed corn from Ukraine in the past week, European traders said.

"U.S. origins lack competitiveness on the international stage, which naturally limits the potential for a rebound," consultancy Agritel said. (Reporting by Tom Polansek in Chicago. Additional reporting by Gus Trompiz in Paris and Naveen Thukral in Singapore; editing by Mrigank Dhaniwala, Jason Neely and Jonathan Oatis)