Seoul, Nov 19 : South Korea has secured a total of 1.5 trillion won ($1.16 billion) in investment commitments from four US companies on the occasion of President Yoon Suk Yeol's attendance at the Asia-Pacific Economic Cooperation (APEC) summit, the government said on Sunday. The industry ministry said that GM, DuPont, IMC and Ecolab have declared commitments to invest in South Korea on the occasion of Yoon's attendance at this year's APEC summit in San Francisco. The ministry said it anticipates the investments by these four companies will lead to an annual export expansion and import substitution effect of over 4.5 trillion won, reports Yonhap news agency. The ministry said GM's investment decision was a result of the government's efforts to improve the investment environment, including regulatory reforms and institutional improvements to attract investment from global companies. On the sidelines of the APEC summit last week, Yoon met with GM Senior Vice President Shilpan Amin, who expressed his confidence in South Korean businesses' operations in light of the government's bold regulatory reforms and institutional improvements in line with global standards. DuPont has decided to invest more than 200 billion won in South Korea to expand its semiconductor material and component production facilities, and research and development center, aiming to create over 100 new jobs. IMC, a unit of global investment company Berkshire Hathaway, plans to invest in production facilities for tungsten oxide used in semiconductor manufacturing. Ecolab plans to invest in production facilities for high-purity nano particles, essential for the production of CMP slurry used in semiconductor manufacturing, the ministry said. /IANS