* Thailand announces reopening rules for tourism reboot * Indonesian rupiah declines 0.4% * China warns latest COVID-19 outbreak could spread further By Anushka Trivedi Oct 25 (Reuters) - Asian stocks were mostly flat to slightly higher on Monday as a fresh COVID-19 outbreak in China added to worries about slowing growth in the world"s second-biggest economy, while the Thai baht climbed on a revival in the country"s tourism sector. Malaysia, Indonesia, South Korea and Singapore shares traded flat to 0.2% higher, while Philippine stocks slipped 0.7%. China, already struggling with a power crunch and crisis in its real estate sector, on Sunday warned that its latest COVID-19 outbreak - across 11 provinces - was likely to spread further, with authorities discouraging travel in an attempt to contain it. Market watchers worried that new curbs could be imposed in the country, which could see economic growth and trade with its Asian partners slow. The Chinese yuan opened 0.1% weaker on the news. There could be "aggressive measures to control virus spreads," said Yeap Jun Rong, market strategist at retail trading platform IG, "which may put a cap on growth, thereby potentially putting risk appetite in the region on hold over the coming days." Meanwhile, the Indonesian rupiah dropped 0.4% to a nearly two-week low as the coal exporter"s currency continued to suffer from tumbling prices of the commodity. Singapore"s dollar and the South Korean won firmed 0.3% and 0.6%, respectively, while most other Asian currencies were tepid. Further investment clues for South Korea will come with third-quarter gross domestic product (GDP) data due on Tuesday. Asia"s fourth-largest economy is expected to have expanded by 0.6% from the previous quarter on robust exports. Leading gains in the region, the Thai baht rallied 0.8% to hit more than a one-month high after the trade and tourism-reliant economy announced rules for its quarantine-free reopening to visitors from 45 countries. Investor confidence in the Thai economy had waned due to collapse of its tourism sector as exports also struggled after the pandemic, with the baht becoming Asia"s worst-performing currency this year. HIGHLIGHTS ** Singapore"s 10-year benchmark yield is down 3 basis points at 1.733%​​ ** Indonesian 10-year benchmark yields are down 2.4 basis points at 6.159% ** In the Philippines, top index losers are Ayala Land Inc , down 4.1%, and Aboitiz Equity Ventures Inc, down 2.5% Asia stock indexes and currencies at 0342 GMT COUNTRY FX RIC FX DAILY % FX YTD % INDEX STOCKS DAILY % STOCKS YTD % Japan -0.18 -9.18 -0.99 3.92 China +0.04 +2.28 0.36 3.52 India +0.00 -2.44 0.00 29.56 Indonesia -0.42 -0.99 0.08 11.21 Malaysia +0.00 -3.09 0.18 -2.23 Philippines +0.02 -5.36 -0.66 1.42 S.Korea +0.63 -7.14 0.40 5.04 Singapore +0.26 -1.73 0.01 12.71 Taiwan +0.11 +2.20 0.20 14.86 Thailand +0.75 -9.57 -0.53 12.79 (Reporting by Anushka Trivedi in Bengaluru; Editing by Kenneth Maxwell)