Norway's $1.7 trillion wealth fund may have to divest shares of companies that violate the fund watchdog's new, tougher interpretation of ethics standards for businesses that aid Israel's operations in the West Bank. The Council on Ethics for the world's largest sovereign wealth fund sent an August 30 letter to the finance ministry, seen by Reuters, that summarizes the recently expanded definition of unethical corporate behavior. The letter did not specify how many nor name companies whose stocks might be sold but suggested it would be a small number, should the board of the central bank, which has the final say, follow recommendations that the council makes. The fund has been an international leader in the environmental, social and governance (ESG) investment field. It owns 1.5% of the world's listed shares across 8,800 companies, and its size carries influence.