Profits at China's major industrial firms maintained solid growth in the first quarter despite a complex economic environment, with equipment manufacturing and high-tech sectors reporting strong gains, official data showed on Monday.

Industrial enterprises with an annual main business revenue of at least 20 million yuan ($2.82 million) saw their total profits rise 15.5 percent year-on-year to 1.696 trillion yuan during the first quarter, 0.3 percentage points faster than the growth recorded in the January-February period, data from the National Bureau of Statistics showed.

In March alone, profits at major industrial firms rose 15.8 percent year-on-year, up 0.6 percentage points from the pace set in January-February, the NBS said.

The robust growth in industrial profits was supported by more proactive macroeconomic policies, according to Yu Weining, a statistician with the bureau.

"In the first quarter, amid multiple economic headwinds, policymakers stepped up macroeconomic regulation and front-loaded more proactive and effective macroeconomic policies, helping the industrial economy recover steadily," Yu said.

Notably, strong gains in equipment manufacturing and high-tech sectors, coupled with double-digit profit growth in the raw materials manufacturing sector, pointed to continued improvement in industrial firms' profitability, Yu said.

According to the NBS, profits in equipment manufacturing industries surged 21 percent year-on-year during the first three months of the year, contributing 6.8 percentage points to the overall profit growth of major industrial firms. Meanwhile, profits in high-tech manufacturing jumped 47.4 percent, contributing 7.9 percentage points to overall industrial profit growth.

The raw materials manufacturing sector posted double-digit profit growth, with profits jumping 77.9 percent year-on-year in the first quarter, maintaining robust momentum, the NBS said.

During the first quarter, profits recorded by mining firms increased 16.2 percent year-on-year, and those registered by manufacturing companies rose 19.1 percent. Profits recorded by industrial firms that offer supplies of electricity, heat, gas, and water fell 3.2 percent, the NBS said.

Despite the strong momentum, NBS statistician Yu cautioned that the external environment remains volatile, with near-term uncertainties still weighing on the outlook, while the mismatch between strong domestic supply and weak demand has yet to be addressed.

Looking ahead, Yu said more efforts should be made to promote both qualitative improvement and reasonable quantitative growth in the industrial economy so as to further consolidate the foundation for continued improvement in industrial firms' profitability.