China's crude imports rose a stronger-than-expected 7.9 percent in November from a year earlier, even though growth in fuel demand remained subdued in the world's second-largest consumer, suggesting the country may be boosting its reserves.

November crude imports at 25.41 million tonnes, or 6.18 million barrels per day (bpd), were up 9 percent on a daily basis from October, data from China's General Administration of Customs showed on Monday.

For the first 11 months of the year, China's crude imports rose to 278 million tonnes, or 6.08 million bpd, up 9 percent from the same period last year, the customs data showed.

The International Energy Agency (IEA) has revised up slightly its forecast for China's oil demand in 2014, estimating demand will rise 2.5 percent, compared to the 2.3 percent predicted in September, on the back of state stockpiling after global oil prices fell to a five-year low.

Total fuel demand has been capped for most of the year by a slowing economy, which has taken its toll on demand for diesel, the main fuel used in the construction and transportation sectors, although demand for motor gasoline and aviation fuel has remained relatively healthy.

The IEA said the the filling of state reserves probably continued into the fourth quarter.

"This would bring the total unreported stock build to 105 million barrels so far in 2014, well above the 89 million barrels posted in 2012 when a portion of Phase 2 State Petroleum Reserves (SPR) capacity was filled," IEA said in its November report.

China's strategic reserves may be holding double the amount of crude revealed in official plans, as companies take advantage of a dive in prices.

Second-largest refiner PetroChina boosted its purchases in the Asian spot market in October, soaking up nearly 24 million barrels of Middle Eastern crude, which traders and refinery sources said would largely end up in storage.

China also imported 2.37 million tonnes of oil products in November and exported 2.44 million tonnes, leaving net oil product exports at 70,000 tonnes, customs data showed.