Chinese solar-panel makers received subsidies, a European Union investigation showed, increasing the likelihood of EU tariffs on imports of the renewable-energy technology from China to counter trade-distorting government aid.

The European Commission has concluded in a probe opened last November that Chinese manufacturers of crystalline silicon photovoltaic modules or panels, and cells and wafers used in them, benefited from preferential lending, tax programs and other aid, an EU official said today in Brussels. The inquiry is one of two that the commission is conducting into alleged unfair Chinese trade in solar goods -- the biggest EU commercial fight of its kind.

The commission, the 28-nation EU’s regulatory arm, on Aug. 2 approved an agreement with China to curb Chinese shipments of solar panels as part of a parallel probe into below-cost sales, a practice known as dumping. The accord, which took effect Aug. 6, sets a minimum price and a volume limit on EU imports of Chinese solar panels until the end of 2015. Chinese manufacturers that take part are being spared provisional EU anti-dumping duties as high as 67.9 percent.