SHANGHAI, July 17 (Reuters) - China stocks struggled for momentum on Wednesday, with major indexes trading in narrow ranges, as investors awaited policy news from a key leadership gathering in Beijing that is expected to end on Thursday.

Sentiment also remained low after data on Monday showed the world's second-largest economy grew much slower than expected in the second quarter as a protracted property downturn and worries over jobs knocked the wind out of a fragile recovery.

Market participants are also worried that China will figure heavily in Donald Trump's foreign policy thinking if he wins the U.S. presidential race.

His choice of J.D. Vance as his vice presidential running mate provides more evidence of what would be a tough U.S. stance on China in a second Trump administration, analysts said.

With business and consumer sentiment near record lows, the Communist Party plenum will seek to inject confidence in the world's second largest economy.

However, conflicting goals such as boosting growth while cutting debt may mean little progress toward implementing change.

** At the close, the Shanghai Composite index was down 0.45% at 2,962.85.

** The blue-chip CSI300 index was up 0.09%, with its financial sector sub-index higher by 1.01%, the consumer staples sector up 1.91%, the real estate index up 2.43% and the healthcare sub-index up 2.31%.

** At the close of trade, the Hang Seng index was up 11.43 points, or 0.06%, at 17,739.41. The Hang Seng China Enterprises index fell 0.3% to 6,297.49.

** The sub-index of the Hang Seng tracking energy shares dipped 4.4%, while the IT sector dipped 0.13%, the financial sector ended 0.35% higher and the property sector rose 1.33%.

** The smaller Shenzhen index ended down 0.78% and the start-up board ChiNext Composite index was unchanged.

** Around the region, MSCI's Asia ex-Japan stock index was weaker by 0.07%, while Japan's Nikkei index closed down 0.43%. (Reporting by Shanghai Newsroom; Editing by Subhranshu Sahu)