Tencent's (HKG:0700) two directors it named to the board of Epic Games resigned after the US Justice Department said the positions violated antitrust rules, according to a Wednesday release by the DOJ.

The two directors resigning are David Wallerstein, a longtime Tencent executive, and Ben Feder, a managing partner of Titra Ventures, Bloomberg News reported Thursday, citing an email sent to the newswire.

Tencent holds a minority stake in Epic, which is a direct competitor of Tencent subsidiary Riot Games.

The US DOJ said it is beefing up its enforcement of the Clayton Act, which disallows directors from serving on the boards of competitors, such as Epic and Riot Games.

"Scrutiny around interlocking directorates continues to be an enforcement priority for the Antitrust Division," according to a statement by Miriam Vishio, DOJ Antitrust Division Deputy Director of Civil Enforcement.

Tencent has also made changes to its shareholder agreement with Epic to give up its rights to director seats or observers, the DOJ said.

Shares jumped 3% during Friday's midday trading.