The U.S. Department of Justice has asked for additional information from Charles Schwab and TD Ameritrade on the proposed mega-deal that would enable Schwab to acquire TD Ameritrade, Schwab and TD Ameritrade confirmed Thursday.

Such a request is not unusual in a deal the size of this proposal, said Schwab. The Department of Justice, which is is responsible for reviewing all large corporate mergers to examine anti-trust concerns, declined to comment on the request.

Tom Nally acknowledged the request for more information at the Firm’s LINC conference in Orlando, Fla., on Wednesday. TD Ameritrade said it still anticipates the deal to close in this year's second half.

The acquisition, which was originally announced last November, would create a brokerage with $5.1 trillion in client assets and 24.1 million accounts. Schwab controls roughly half of the market and TD Ameritrade now ranks as the third-largest player, with up to 20% of the market, according to news reports.

The deal has been reported as an all-stock $26 billion arrangement. Shares in both companies increased following the original announcement. Both companies submitted additional filings with the Justice Department on Wednesday.  

Mergers and acquisitions of all sizes continue to grow in number and in scope, and more activity is expected in the future, industry insiders say.