BEIJING, Dec 1 (Reuters) - Growth in Chinese factories stalled in November as output shrank for the first time in six months, reinforcing expectations that authorities will roll out more aggressive support measures after unexpectedly cutting interest rates to shore up growth.

After saying for months that China does not need any big economic stimulus, the central bank surprised financial markets by lowering rates on Nov. 21. Analysts see more moves in coming months if the economy continues to stumble.

The final HSBC/Markit China Manufacturing Purchasing Managers' Index (PMI) edged down to 50 in November, a six-month low and right on the boom-bust 50-point level that separates growth from contraction on a monthly basis.

The reading was unchanged from a preliminary "flash" figure and down from the final 50.4 in October.

Output fell to 49.6, the worst since May, as companies scaled back production in the face of "muted growth in new work" and subdued market conditions, HSBC/Markit said.

Export growth, which had strengthened recently, also slackened to a five-month trough, though it still expanded.

The HSBC focuses more on small and medium-sized firms, which are facing more stresses as cooling demand cuts into sales and rising financing costs make it tougher to pay off debts.

A similar government study on Monday, which focuses more on larger, state-owned firms, showed growth in the manufacturing sector slowed to an eight-month low in November, with domestic demand cooling and export demand contracting.

The gloomy PMI reports reinforce expectations that the world's second-largest economy has lost steam despite a flurry of government measures to lift growth, fuelling bets that further policy loosening is on the cards.

Hurt by a sagging property market, unsteady export growth and cooling domestic demand and investment, China's economic growth is expected to slow to a 24-year low of 7.4 percent this year, though the fourth quarter is shaping up to be possibly weaker than earlier thought.

Growth is expected to cool further to 7.1 percent in 2015, a Reuters poll showed.

"Disinflationary pressures remain strong while the labour market weakened further," said Qu Hongbin, the chief economist at HSBC, while noting that China's rate cut last week should bolster property and manufacturing investment.

"We continue to expect further monetary and fiscal easing measures to offset downside risks to growth."

Sources familiar with China's policy-making said leaders are prepared to cut rates again and loosen lending curbs on concerns that falling prices could cause a spike in bad loans.