Thomson Reuters Corp. (TRI) is seeking shareholder approval to unify its dual-listed company structure, a move that would simplify trading as U.K. investors make up a shrinking portion of the financial data company's shareholder base.

In connection with the unification, Thomson Reuters said it may repurchase the equivalent of up to $500 million of its shares in one or more of its markets.

If the plan is approved at a shareholder meeting scheduled for Aug. 7, Thomson Reuters would remained listed on the Toronto Stock Exchange and the New York Stock Exchange, but wouldn't be listed on the London Stock Exchange or Nasdaq.

The company, which was formed via a merger of Thomson Corp. and Reuters Group, said Thomson Reuters PLC (TRIN) shareholders would have "the same economic interest" in Thomson Reuters as they do under the current dual-listed company structure. Thomson Reuters PLC shareholders would receive one share in Thomson Reuters Corp. for every PLC share held. Holders of Thomson Reuters Corp. common stock, meanwhile, would continue to hold their existing shares.

"When we formed Thomson Reuters, we believed a DLC structure was the best way for Reuters shareholders to stay invested in our shares and participate in our growth," said Thomson Reuters Chief Executive Thomas Glocer. "However, the shareholders of Thomson Reuters have changed considerably, and U.K. shareholders now only constitute 5% of the combined shareholder base."

The company said the proposed unification wouldn't affect its businesses, operations, strategy or financial position. The company also affirmed its full-year revenue target.

If shareholders and court approvals were obtained, the company said it expects the unification to occur by the end of the third quarter.

Thomson Reuters Corp.'s shares were up 0.3% at $29.19 in after-hours trading.

-By John Kell, Dow Jones Newswires; 201-938-5285; john.kell@dowjones.com