By Colleen Howe

BEIJING (Reuters) -China's solar manufacturers reported losses this week as U.S. President Donald Trump's trade war put further pressure on demand in an industry where top manufacturers were already facing low prices and tariffs on exports to the United States.

Top producers Longi Green Energy and JinkoSolar both reported a net loss of 1.4 billion yuan ($193 million) for the first quarter, while losses for peers JA Solar and Trina Solar totalled 1.6 billion yuan and 1.3 billion yuan, respectively.

Longi, which also turned in a net loss of 8.6 billion yuan for 2024, told analysts in a call that demand for solar products was expected to be flat year-on-year in 2025.

"During the reporting period, solar industry supply chain prices were at a low level, combined with overseas trade policies impacting demand, all segments of the industry were under pressure," said Jinko, where losses increased from 473.7 yuan in the fourth quarter of last year.

The company's sales of solar products, including silicon wafer, solar cells and modules, fell 12.68% year-on-year to 19,130 megawatts in the quarter.

Jinko said it saw the fastest growth in the Asia Pacific and Africa regions, although China, the U.S. and Europe remain the largest markets.

Even before Trump's trade war, in which he has levied 145% tariffs on imports of Chinese goods, Chinese solar exports were facing tariffs in the U.S., the second-biggest solar market after China.

As a result, Chinese manufacturers had set up production bases in third countries in Southeast Asia - countries that U.S. manufacturers later targeted with trade cases alleging they were flooding the market with cheap goods.

In response to one of those cases, the U.S. last week finalised tariffs of as high as 3,500% on solar products from Chinese solar manufacturers with factories in Malaysia, Cambodia, Thailand and Vietnam.

The U.S. made up about 5% of Jinko's sales in the quarter, it said in its investor call.

In addition to solar products, tariffs were also making it prohibitively expensive to sell battery storage systems to the U.S., Jinko told investors.

Meanwhile, CSI Solar, a NASDAQ-listed subsidiary of China's Canadian Solar, plans to accelerate the relocation of manufacturing to low-tariff regions and is negotiating with major clients and suppliers to reasonably share tariff costs, it said in a filing with the U.S. Securities and Exchange Commission on Monday.

At the same time, CSI said it was preparing for potential U.S.-China negotiations and the adjustment of tariffs to a more reasonable range, while also pursuing tariff exemptions for some products.

(Reporting by Colleen HoweEditing by Mark Potter)