(Reuters) - Chinese state-owned firms bought at least 1 million tonnes of U.S. soybeans on Friday, a day after high-level bilateral talks yielded progress toward a trade deal and a Chinese commitment to buy more U.S. soybeans.

Acres of soybeans seen at the Pioneer-DuPont Seed facility in Addieville, Illinois U.S., September 19, 2018. Picture taken September 19, 2018. REUTERS/Lawrence Bryant

The purchases are slated for shipment between April and July, with a large share expected from U.S. Gulf Coast export terminals, three traders with knowledge of the deals said.

One trader with direct knowledge of the deals said total purchases were around 2.2 million tonnes. The other two traders said the sales were similar to three recent waves of buying in which state-owned firms booked 1 million to 1.5 million tonnes of soybeans.

U.S. soybean futures Sv1 rallied to multi-month highs on Friday on news of renewed demand from the world's top importer.

But the market’s gains were restrained by worries that Chinese purchases will hardly dent massive soybean stockpiles in the United States and around the world. The looming harvest of a large soy crop in Brazil, the world’s top supplier, further capped prices.

“It certainly is good to see some concessions and more buying interest from China, but this is a concession in terms of a larger trade agreement. Brazilian offers are cheaper than we are so it’s just part of the negotiation,” said Terry Linn, analyst with Chicago-based brokerage Linn & Associates.

Friday’s purchases by state-owned firms were believed to be destined for China’s state reserves, and thus immune from high import tariffs on U.S. beans. The 25 percent tariffs, imposed last summer in retaliation for U.S. tariffs on Chinese goods, remain in place for U.S. soy imports by commercial crushers in China.

Exports to China have plummeted this season during a bitter trade dispute, with swelling supplies sending prices to near decade lows last autumn and U.S. farmers struggling to turn a profit.

China has been buying most of its soybeans from Brazil, which is in pace to harvest a bumper crop in the coming months.

Friday’s sales bring China’s total purchases of the 2018 U.S. soybean harvest to at least 6.5 million tonnes, a fraction of its traditional annual haul from the United States of more than 30 million tonnes.

Through January of 2017, more than 29.4 million tonnes of that season’s harvest had already been shipped to China, with another 4 million tonnes sold and awaiting shipment, according to U.S. Department of Agriculture data.

Benchmark Chicago Board of Trade March futures climbed to $9.31-1/4 a bushel on Friday, the highest point for a most actively traded soy contract Sv1 since mid-June. Beijing slapped steep tariffs on U.S. soybeans on July 6, effectively halting all U.S. shipments to their top customer.

Before Friday’s sales, China had previously booked an estimated 5 million tonnes of U.S. soybeans in three waves of purchases since U.S. President Donald Trump and his Chinese counterpart Xi Jinping agreed to a trade war detente on Dec. 1.

After high-level trade talks in Washington this week, Chinese Vice Premier Liu He announced on Thursday China would buy an additional 5 million tonnes.