(REUTERS) -- Deutsche Telekom and AT&T withdrew their application for approval by the Federal Communications Commission of a planned $39 billion deal for T-Mobile USA to focus on obtaining the green light from the Department of Justice.

At the same time, AT&T said on Thursday it expected to book a pretax $4 billion charge in this quarter for potential break-up fees, should the deal collapse.

This formal step today is being undertaken by both companies to consolidate their strength and to focus their continuing efforts on obtaining antitrust clearance for the transaction from the Department of Justice, the companies said in a statement.

They added that they are continuing to pursue the sale of T-Mobile USA to AT&T.

The withdrawal follows after the Federal Communications Commission said earlier this week it planned to send the deal to an administrative law judge for review.

The U.S. Department of Justice went to court in August to oppose AT&T's purchase of T-Mobile from Deutsche Telekom on antitrust grounds. A trial in that case is due to begin on February 13.

Deutsche Telekom shares were up 0.7 percent at 8.796 euros by 0825 GMT, while AT&T shares were down 0.2 percent in Frankfurt. The STOXX Europe 600 Telecommunications index was up 0.1 percent.

(Reporting by Harro ten Wolde)