Seoul, Sep 15 Seoul stocks closed lower for the fourth consecutive session on Tuesday, as investors digest macro uncertainties, and the latest calls from artificial intelligence (AI) leaders that the industry should slow down the pace of development. The Korean won slid against the US dollar.The benchmark Korea Composite Stock Price Index (KOSPI) fell 57.11 points, or 0.85 percent, to 6,627.26.Trade volume was light at 274 million shares worth 16.2 trillion won (US$11.9 billion). Losers outnumbered winners 621 to 253, reports Yonhap news agency.Retail investors were net buyers, snatching up 833.13 billion won. Institutional and foreign investors offloaded a combined…