CHICAGO, July 13 (Reuters) - Corporate governance experts said Whole Foods Market should launch an internal investigation into chat room postings made by John Mackey, chief executive, under an alias that boosted his company and were critical of rivals.

The Wall Street Journal, citing people familiar with the matter, reported on Friday that the Securities and Exchange Commission had launched an informal probe of Mr Mackey’s postings, in a sign the issue will not go away any time soon.