WASHINGTON—President Joe Biden signed an executive order on June 3, amending a Trump-era ban that prohibited American investors from investing in Chinese military companies. The new order expands the previous prohibition list by adding more Chinese defense and surveillance technology companies. The order also moves the authority of selecting targeted companies to the Treasury Department from the Defense Department. Biden’s order expands the scope of the national emergency declared by former President Donald Trump last year and bans more companies involved in “the development or use of Chinese surveillance technology to facilitate repression or serious human rights abuse.” The order “prohibits United States persons from engaging in the purchase or sale of any publicly traded securities” of 59 entities listed in the annex of the executive order. Blacklisted companies include telecoms equipment maker Huawei, video surveillance manufacturer Hikvision, aerospace firm Aviation Industry Corp. of China and state-run mobile operators China …