* Tightening fears, inflation keep markets under pressure
* Hang Seng index down 0.3 percent, H-shares underperform
* Shanghai Comp slips 0.7 percent, banks weigh (updates to midday)
By Vikram S.Subhedar and Chen Yixin
HONG KONG/SHANGHAI, Jan 24 (Reuters) - Shares fell in Shanghai and Hong Kong on Monday, with the materials sector the biggest laggard as investors fretted over the impact of tightening measures on growth.
Fears that Chinese authorities will take more aggressive steps to put a lid on rising inflation have dented the strong start for Hong Kong shares this year and have kept mainland investors on the defensive.
Hong Kong's Hang Seng index fell for a third successive day, down 0.3 percent at 23,795.8 by the midday trading break. The index has lost 2.5 percent after hitting a high for the month of 24,420 last week.
China's key stock index lost 0.5 percent weighing on the shares of Hong Kong-listed mainland firms. The China Enterprises Index fell 0.9 percent.
"Inflation pressures in China are very, very high and are not restricted only to food," said Larry Jiang, chief investment strategist at Guotai Junan Securities in Hong Kong, adding that the good start to the year had raised expectations that the Hang Seng would rise above the 2010 high around 25,000.
"When that didn't work out, I think people were disappointed. Some foreign investors who got into Hong Kong late probably feel that the pace of tightening is going to get quicker," said Jiang.
Data on Friday from fund tracker EPFR for the week ended Jan. 19 showed outflows of $254 million from greater China equity funds, their worst week since early in the second quarter of last year.
The materials sector was weak with the sector sub-index down 1.6 percent. China Coal fell 2.4 percent and was the top loser on the Hang Seng index.
Angang Steel , down 3.1 percent, continued its slide after reporting weaker-than-expected results week. Its shares have fallen nearly 9 percent after the company's forecast of a fourth-quarter loss disappointed investors.
Bucking the broader weak trend in the market, shares of Bank of East Asia gained 1.9 percent on healthy turnover after it agreed to sell an 80 percent stake in its U.S. operations to Industrial & Commerical Bank of China for $140 million.
SHANGHAI WEAK
Lingering worries over more monetary tightening, including an imminent official interest rate hike, kept mainland markets under pressure with the benchmark continuing its underperformance among regional Asian peers.
The Shanghai Composite Index was at 2,701.8 points at midday, extending last week's 2.7 percent. It is now trying to find a support above the 2,655-2,677 gap it created in early last October, analyst said.
"Expectations of further tighting steps hurt investors' confidence," said Wang Aochao, a senior analyst at UOB Kay Hian in Shanghai. "We think the index still has room to fall."
Keeping investors edgy was a report in official newspaper Securities Times that cited analysts at securities firms saying the week before and after the Lunar New Year was the most sensitive period when the central bank could announce an interest rate hike.
Chinese markets will be shut next week for the new year holiday.
Nearly all the 16 banks listed on the Shanghai and Shenzhen stock exchange underperformed the index on Monday, with Construction Bank dropping 1.5 percent and Agricultural Bank of China down 1.2 percent.
Industrial and Commercial Bank of China (ICBC) , the world's largest lender by market capitalisation, fell 0.5 percent after it said it would buy Bank of East Asia's U.S unit.
Property firms came under pressure after the Ministry of Housing and Urban-Rural Development required some cities to introduce a detailed regulation on curbing the housing market.
Shanghai mayor Han Zheng reiterated the city's intention to push ahead with a trial run of a property tax aimed at cooling speculation in the red hot real estate sector.
The top listed developer Vanke fell 0.5 percent, while Zhonthong Real Estate , dropping 8.4 percent. (Editing by Alex Richardson) ($1=6.6 Yuan) Pan-Asia...... Japan........ S.Korea.... S.E. Asia............ Hong Kong... Taiwan..... Australia/NZ......... India....... China......
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