WARSAW (Reuters) - Polish explosives maker Nitro-Chem signed a deal on Wednesday to supply explosives worth 1.2 billion zlotys ($310 million) to a U.S. firm, intended for the U.S. military, the deputy defence minister said.

"We are talking about a colossal contract," the minister, Cezary Tomczyk, told reporters after the signing, adding that the deal provided for delivery of 18,000 tons of TNT to the United States over three years.

From 2027 to 2029, TNT, or trinitrotoluene, will be supplied to U.S. firm Paramount Enterprises International by Nitro-Chem, a subsidiary of Poland's state-owned defence group PGZ, group spokesperson Jacek Matuszak told Reuters.

The deal is bigger than deals both companies signed in 2023 and 2024 for deliveries of TNT to supply U.S. government weapons programs in 2025 and 2025 respectively and intended for tasks such as the filling of artillery shells and aerial bombs.

"This deal's value exceeds that of either of the two earlier ones," Matuszak said. "The TNT that is now being contracted will be used for the needs of the United States armed forces, including the production of 155-mm ammunition."

The new deal did not require expansion of Nitro-Chem's production lines or new hiring, he added, saying, "We are able to fulfill this order with the current workforce and our current infrastructure."

Nitro-Chem is Europe's largest producer of TNT and one of the world's largest, its website says.

($1=3.8854 zlotys)