HONG KONG (AFX-ASIA) - Morgan Stanley Dean Witter said it has cut its forecast on non-Japan Asia's GDP growth to 5.0 pct in 2001 as regional economic development remains in a quagmire, chief economist Stephen Roach said. "We have sliced about half a percentage point off our non-Japan Asia's growth estimates to 5.0 pct and 6.0 pct for 2001 and 2002, respectively," Roach said.