China's economic growth edged down to 6.8% in the final quarter of 2015 as trade and consumer spending weakened, dragging full-year growth to its lowest in 25 years.

Growth has fallen steadily over the past five years as the ruling Communist Party tries to steer away from a worn-out model based on investment and trade toward self-sustaining growth driven by domestic consumption and services.

But the unexpectedly sharp decline over the past two years prompted fears of a politically dangerous spike in job losses.

Full-year growth declined to 6.9%, government data showed on Tuesday. That was the lowest since sanctions imposed on Beijing following its crackdown on the Tiananmen Square pro-democracy movement caused growth to plummet to 3.8% in 1990.

The October-December growth figure was the lowest quarterly expansion since the aftermath of the global financial crisis, when growth slumped to 6.1% in the first quarter of 2009. Growth in the July-September quarter of 2009 was 6.9%.

Growth in investment in factories, housing and other fixed assets, a key economic driver, weakened to 12% in 2015, down 2.9 percentage points from the previous year. Retail sales growth cooled to 10.6% from 2014's 12%.

"The international situation remains complex," said Wang Bao'an, commissioner of the National Bureau of Statistics. "Restructuring and upgrading is in an uphill stage. Comprehensively deepening reform is a daunting task."

Growth was in line with private sector forecasts and the ruling Communist Party's official target of about 7% for the year.

Beijing responded to ebbing growth by cutting interest rates six times since November, 2014, and launched measures to help exporters and other industries. But economists note China still relies on state-led construction spending and other investment.

December exports shrank 1.4% from a year earlier, well below the ruling party's target of 6% growth in total trade. For the full year, exports were down 7.6%, a blow to industries that employ millions of Chinese workers.

Forecasters expect economic growth to decline further this year, with the International Monetary Fund targeting a 6.3% expansion.