President Bush's chief ethics adviser is pressing Secretary of State James Baker to divest his stock in Chemical New York Corp., a bank holding company with $4.5 billion in loans to the Third World, The Washington Post reported Friday. White House counsel C. Boyden Gray has been arguing that Baker should sell the stock to avoid the appearance of a conflict of interest. Gray is following Bush's orders for tough ethical standards. Baker wants to keep his bank stocks, arguing he can continue the practice he observed as Treasury secretary. Under that practice, Baker would remove himself from matters particularly associated with Chemical and seek a "presidential waiver" of normal conflict-of-interest regulations to allow him to participate in broader matters that might affect the bank.