SHANGHAI, April 30 (Reuters) - China's stock market indexes posted their biggest monthly gains for the year in April, although weakness in banks on Thursday offset sharp gains in small-cap shares.
Smaller companies grabbed the spotlight ahead of a planned cross-border investment scheme between Shenzhen and Hong Kong.
The CSI300 index of the largest listed companies in Shanghai and Shenzhen fell 0.5 percent, to 4,749.89, while the Shanghai Composite Index lost 0.8 percent, to 4,441.66 points.
The CSI300 index was up 17.3 percent for April while the SSEC gained 18.5 percent, the biggest monthly gains since December.
Reflecting sustained optimism, Chinese fund managers will raise the proportion of their portfolios invested in stocks over the next three months, a Reuters poll showed.
Banking shares sagged for the second day, after China's biggest lenders posted their slowest first-quarter profit growth in at least six years as a cooling domestic economy squeezed lending margins and led to a jump in soured loans.
But the Shenzhen market, home to China's listed start-up companies and small- and medium-sized enterprises was strong, on expectations that China will announce the timetable for the Shenzhen-Hong Kong Stock Connect scheme next month.
Real Estate stocks also jumped, after the National Development and Reform Commission, China's planning agency, said the property market shows signs of recovery, with March transaction volumes in 90 major Chinese cities rising 40.2 percent from the previous month.
For the trading week, which is shortened by Friday's Labour Day holiday, the CSI300 was up 1.0 percent while the SSEC gained 1.1 percent. (Reporting by the Samuel Shen and Kazunori Takada; Editing by Jacqueline Wong)