By David Shepardson

WASHINGTON, June 28 (Reuters) - U.S. President Donald Trump on Wednesday said he planned to nominate a Federal Communications Commission attorney to fill one of two vacant seats at the nation's telecommunications regulatory agency.

The White House said Trump would name Brendan Carr, a Republican who previously served as an adviser to FCC Chairman Ajit Pai, to an open seat. Carr currently is general counsel at the FCC and also has worked at the Wiley Rein LLP law firm.

Carr did not respond to a request for comment.

The five-seat FCC currently has only three members. Earlier this month, Trump nominated Jessica Rosenworcel, a Democrat, to another open seat at the FCC. The U.S. Senate must confirm both Carr and Rosenworcel before they can be seated.

Rosenworcel served as a commissioner for the regulator until the end of 2016 when lawmakers failed to take up her renomination under former President Barack Obama, giving Republicans a 2-1 majority on the five-seat commission.

The FCC is working to reverse a number of Obama-era regulations, including the former Democratic president's landmark 2015 net-neutrality rules prohibiting broadband providers from giving or selling access to certain internet services over others.

Pai, chosen by Trump in January to head the agency, also has said he wants to dismantle other significant regulations as part of a sweeping review he said would remove barriers to business and modernize rules. Pai also has proposed significant changes to local TV ownership limits and plans other changes to media regulations.

Pai praised Carr's appointment. "Brendan’s expertise on wireless policy and public safety will be a tremendous asset to the commission," he said in a statement.

Republican Michael O'Rielly and Democrat Mignon Clyburn also serve on the commission.

Democrats insisted Republicans had agreed in 2015 to reconfirm Rosenworcel as part of a deal to confirm O'Rielly. Republicans denied there was a deal but the standoff had delayed consideration of telecommunications legislation in the Senate.

Pai would be forced to leave the commission if he is not reconfirmed by the Senate by the end of the year.

Under Pai, the FCC chose not to review AT&T Inc's planned $85.4 billion acquisition of Time Warner Inc.

The FCC must review Sinclair Broadcast Group Inc's proposed $3.9 billion acquisition of Tribune Media Co, one of the largest U.S. TV station operators. (Reporting by David Shepardson; Editing by Bill Trott)