UPDATE 3-Mark Cuban fails to end SEC insider trading lawsuit
* Billionaire accused of insider trading in Mamma.com
* SEC says Cuban sold 6.3 percent stake following tip
* Cuban has denied wrongdoing
By Jonathan Stempel
March 5 (Reuters) - Mark Cuban, the billionaire owner of the National Basketball Association's Dallas Mavericks, on Tuesday lost a bid to throw out a U.S. regulator's civil fraud lawsuit accusing him of insider trading in a 2004 stock sale.
U.S. District Judge Sidney Fitzwater in Dallas said the U.S. Securities and Exchange Commission may continue to press its case against Cuban, which began more than four years ago.
The SEC said Cuban avoided more than $750,000 of losses by selling his 600,000 Mamma.com Inc shares in June 2004, after learning about an equity offering that would dilute his 6.3 percent stake in the Montreal-based search engine company.
Fitzwater said the question of whether the case against Cuban could be dismissed was "in some respects a close one," but that the SEC ultimately deserved a chance to present its arguments to a jury.
Cuban is worth $2.4 billion, Forbes magazine said this week. Continued...