The internal watchdog at the U.S. Securities and Exchange Commission has concluded that the accusations of investigative misconduct against the enforcement division by Dallas Mavericks basketball team owner Mark Cuban have no merit, according to a person familiar with the matter.

The SEC sued Cuban in 2008 for insider trading, alleging that he had sold his 6.3 percent stake in in June 2004 after learning confidentially that the Montreal-based search engine company was planning a stock offering. The SEC said Cuban's sale allowed him to avoid more than $750,000 of losses.

(Reporting by Sarah N. Lynch, Editing by Sandra Maler)