After a wave of scandals including wrongful foreclosures on US home mortgages, worker suicides at a major Apple Inc supplier in China and the $1.7 billion(S$2.1 billion) accounting fraud at Japan's Olympus Corp, a New York think tank is calling out companies that take the high road.

The Ethisphere Institute's annual World's Most Ethical companies list, released on Thursday, found that 145 companies in countries including United States, Great Britain, Japan, Portugal and India stood out as setting a high standard for their employees' behavior.

American Express Co, General Electric Co and Starbucks Corp - all of which have made the list six years running - are among the companies that stand out as encouraging employees to voice their concerns, said Alex Brigham, executive director of Ethisphere.

"Do you not only know what you're supposed to do, but if you have a concern around an ethical issue, will you be willing to be report it?" Brigham said. "It's the latter point which is so important."

Companies where employees are willing to report problems are also likely to be places where people are quicker to offer solutions, he reasoned.

Ethisphere evaluated about 5,000 global companies, including all members of the Standard & Poor's 500 index, on reputation, corporate citizenship, culture and other qualities.

Newcomers to the list range from those that focus on social responsibility, including Thrivent Financial for Lutherans and Britain's Ethical Fruit Co, to Portuguese utility EDP Energias de Portugal and US defense consulting company SRA International Inc.