Mike Golic and Trey Wingo speculate about Vince McMahon's plans since selling $100 million of WWE shares. (1:58)

Vince McMahon's plan to perhaps try his hand again at a professional football league came more into focus Thursday.

McMahon is chairman and CEO of World Wrestling Entertainment, which filed details with the U.S. Securities and Exchange Commission about McMahon's sale of 3.34 million shares of WWE, equaling about $100 million.

He did so, the filing noted, "primarily to fund a separate entity from the Company, Alpha Entertainment LLC, which Mr. McMahon established to explore investment opportunities across the sports and entertainment landscapes, including professional football."

The filing comes after WWE confirmed earlier in the week that Alpha Entertainment, which was founded in September, was in fact an entity of McMahon's.

Alpha filed for five trademarks related to the XFL on Dec. 16, according to records with the U.S. Trademark and Patent Office.

The original XFL, a joint venture between Vince McMahon's WWE and NBC, debuted in 2001 and lasted only one season. Ed Bailey/AP Photo

The filings seek to trademark the XFL as a professional football league and also cover merchandise related to the league. Previous XFL trademarks were abandoned over a period of time from 2002 to '05.

The company also sought to trademark "URFL."

Last year, the WWE filed to trademark "He Hate Me," the most famous nickname from the XFL. This week, the trademark was published by the U.S. Patent & Trademark Office for opposition, which means that anyone who objects has to do so in 30 days. The most obvious potential objector would be Rod Smart, who came up with the nickname and wore it on the back of his jersey. Smart had "He Hate Me" trademarked until he abandoned in 2011.

The original XFL, a joint venture between WWE and NBC, debuted in 2001 and lasted only one season.

WWE and NBC lost approximately $35 million each, after taxes, on the league.