Major Chinese industrial firms saw their combined profit rise 12.1 percent year-on-year in the first quarter, slowing from the 17.2-percent rate seen during the January-February period, official data showed Saturday.

Profits at industrial companies with annual revenues of more than 20 million yuan ($3.2 million) amounted to 1.17 trillion yuan in the first three months, the National Bureau of Statistics said in a statement.

In March alone, their profit moved up 5.3 percent year-on-year to 464.9 billion yuan.

The growth came as China's GDP growth unexpectedly slowed to 7.7 percent in the first quarter, after seeing a 7.9-percent expansion during the final quarter of 2012.

In breakdown, private companies outperformed other firms, with combined profits up 17.8 percent year on year in the first quarter. State-run enterprises and overseas-funded companies saw profits up 7.6 percent and 7.1 percent, respectively, during that period.

Revenues from primary businesses at major industrial companies climbed 11.9 percent year-on-year to 22.2 trillion yuan.