China recorded a slowdown in its manufacturing sector last month, underlining the challenges its new leaders face in reviving economic growth.

The official Purchasing Managers’ Index (PMI), which surveys big firms, fell to 50.4 in January from 50.6 in December. This still signified growth but at a slightly reduced pace, according to the Financial Times.

In contrast, a separate PMI for China, published by HSBC to gauge smaller firms, indicated an increase to a two-year high of 52.3 in January from 51.5 the previous month.

The PMI is a key indicator of growth in the sector and a reading above 50 shows expansion.

Analysts said volatility in the two measures was normal and that China remained on course for a moderate recovery in the first half of the year.

“The economy is in the midst of mid-cycle upswing … there is sufficient economic momentum and political impetus to ensure a continuation of the current expansionary phase,” said Alistair Thornton, senior China economist at IHS Global Insight.

China’s manufacturing sector has been one of the biggest drivers of its growth over the past decades. Investors and economists dismissed concerns of the lower official PMI and had forecast a strong performance in January after slowing to 7.8% growth in 2012.