SHANGHAI, April 29 (Reuters) - China stocks ended the session higher on Thursday, underpinned by gains in financials after some heavyweight companies reported robust first-quarter profits, while some mutual funds’ high allocations to the banking sector also lent support. ** At the close, the Shanghai Composite index was up 0.52% at 3,474.90, while the blue-chip CSI300 index was up 0.88% to 5,164.17. ** The smaller Shenzhen index ended up 0.36% and the start-up board ChiNext Composite index was unchanged. ** CITIC Securities Co,, China’s biggest brokerage by assets, reported a 26.7% rise in first-quarter net profit on Wednesday, led by strong growth in commission fees. ** A gauge that measures the performance of the sector, the CSI SWS securities index, finished up 2.44%. ** Bank of Jiangsu hit its upward trading limit earlier in the session, after the lender said its non-performing loan ratio fell to 1.32% at end-March, the lowest level since it was listed. ** Banking shares were up after some mutual funds reportedly increased their allocation to the sector. Data showed that total market value of mutual fund holdings in banks stood at 123.39 billion yuan ($19.07 billion) at end-March, up by 73.44% from the previous quarter. ** Separately, market sentiment was also improved on signs of continued recovery in the tourism sector. ** A spokesperson from the Ministry of Transport told state-run Shanghai Securities News that 265 million passenger trips are expected during the five-day Labor Day holiday starting May 1. The highway traffic volume on the first day of the long holiday is likely to exceed 60 million, reaching a record high. ($1 = 6.4714 Chinese yuan) (Reporting by Winni Zhou and Andrew Galbraith; Editing by Rashmi Aich)