SHANGHAI, May 15 (Reuters) - Mainland China shares inched lower on Wednesday, pressured by U.S. President Joe Biden's decision to levy fresh tariffs on Chinese goods.

** U.S. President Biden on Tuesday unveiled steep tariff increases on an array of Chinese imports including electric vehicle (EV) batteries, computer chips and medical products, risking an election-year standoff with Beijing as he woos American voters who give his economic policies low marks.

** The tariffs are considered as a fresh sign of escalations in Sino-U.S. relations, which have long been one of the key factors influencing Chinese financial markets.

** "We are more concerned China may face similar trade-restrictive measures from other regions," analysts at Nomura said in a note.

"The EU and UK account for about 40% of China's EV exports in 2023, the EV sector may face increased pressure if Europe follows the U.S. and imposes high punitive tariffs on Chinese EVs."

** At the midday break, the Shanghai Composite index was down 0.17% at 3,140.34 points, while China's blue-chip CSI300 index was down 0.27% at 3,647.19 points.

** Property shares outperformed the market after Bloomberg reported, citing unnamed sources, that China is considering a proposal to have local governments across the country buy millions of unsold homes, an attempt to rescue the property market. The real estate index up 5.01% by midday.

** Market did not react much to China's central bank's decision to leave a key policy rate unchanged while rolling over maturing medium-term lending facility (MLF) loans on Wednesday, in line with market expectations.

** The smaller Shenzhen index was unchanged for the day, the start-up board ChiNext Composite index was weaker by 0.13% and Shanghai's tech-focused STAR50 index was down 0.49%.

** Markets in Hong Kong are closed on Wednesday for a public holiday.

** Around the region, MSCI's Asia ex-Japan stock index was firmer by 0.63% while Japan's Nikkei index was up 0.17%.

** The yuan was quoted at 7.2252 per U.S. dollar, 0.11% firmer than the previous close of 7.233.

(Reporting by Shanghai Newsroom; Editing by Mrigank Dhaniwala)