3 MIN. DE LECTURA
* HSI +0.9 pct, H-shares +1.1 pct, CSI300 +1.1
* Hong Kong indexes head for best month since July
* Steel stocks up after China says to support railway industry
* Mengniu rises after Danone's investment in Yashili
HONG KONG, Oct 31 (Reuters) - Shares in Hong Kong and mainland China markets rose on Friday, helped by strength in most heavyweight stocks as investors bet that China's government will roll out more support measures for the economy.
The Shanghai Composite Index rose 0.9 percent to a 20-month high of 2,412.5 points by midday, while the CSI300 of the leading Shanghai and Shenzhen A-share listings climbed 1.1 percent.
For the week, the mainland indexes looked set to gain 4.8 percent and 4.4 percent, respectively. For the month, the indexes were up 2.1 percent and 1.8 percent, respectively.
"Gains by heavyweight stocks helped the main index to climb above 2,400 points - a technically-important level," said Tian Weidong, head of research in Kaiyuan Securities in Xi'an.
"The logic behind their gains is that they are betting on more easing policy from the government to come in the medium to long-term."
Financials sectors provided strong support to main indexes, with Bank of China Ltd rising 3.7 percent, Industrial and Commercial Bank of China Ltd climbing 2.2 percent, and China Life Insurance Co Ltd gaining 2.1 percent.
Steel-related stocks also rose after China announced recently it would further support the railway industry.
Wuhan Iron and Steel Co Ltd rose 6.0 percent, Baoshan Iron&Steel Co Ltd rising 3.4 percent, and Maanshan Iron & Steel Co Ltd surging 7.6 percent.
In Hong Kong, the Hang Seng Index gained 0.9 percent to 23,916.54 points by the lunch break on Friday. The China Enterprises Index of the top Chinese listings in Hong Kong rose 1.1 percent.
Both indexes were up more than 4 percent so far in October, heading for their best months since July.
"The sentiment is back, the market is following the U.S market as Fed stopped QE (quantitative easing) and its economy and employment rate are picking up," said Sam Chi Yung, strategist at Delta Asia Financial Group in Hong Kong.
Analysts said people also were investing in safer shares in sectors such as utilities. China Resources Power Holdings rose 2.5 percent.
The casino shares extended gains after Wynn Resorts Ltd posted better-than-expected quarterly earnings. By midday, Wynn Macau Ltd was up 0.5 percent. Rivals Galaxy rose 3.8 percent, SJM Holdings was up 2.8 percent and Sands China climbed 2.5 percent.
The consumer goods sector was lifted by Mengniu Dairy after Danone SA announced that it would buy a 25 percent stake in Mengniu's controlled Yashili International Holdings Ltd for $550 million.
Mengniu shares climbed 1.9 percent to their highest in 5 weeks. China Modern Dairy Holdings rose 1.8 percent. Yashili shares reversed early gain and were down 6.9 percent. (Reporting by Shanghai Newroom; Editing by Kim Coghill)