(Adds details on Giancarlo for CFTC commissioner)
By Jeff Mason and Alina Selyukh
WASHINGTON Aug 1 (Reuters) - President Barack Obama plans to nominate Senate aide Michael O'Rielly to fill the second Republican seat on the Federal Communications Commission, the White House said on Thursday, bringing the agency closer to operating at full capacity.
The U.S. Senate has yet to confirm Democrat Tom Wheeler as the FCC's chairman and Senate Republicans have indicated they wanted to wait for O'Rielly's nomination to pair the two for a confirmation vote after the chamber returns from an August recess in September.
The White House on Thursday also said Obama plans to nominate J. Christopher Giancarlo, an attorney and currently the executive vice president of GFI Group, as a commissioner for the Commodity Futures Trading Commission and Patrick Pizzella, a former assistant secretary of labor, as a member of the Federal Labor Relations Authority.
Giancarlo would be the first commissioner from the swaps industry, a market dominated by investment banks, with brokers such as GFI playing an essential role as trading platforms.
The CFTC was given extensive new powers to overhaul the $630 trillion swaps market after the 2007-09 credit meltdown, and has been writing scores of new rules to change the structure of the opaque market.
FCC, meanwhile, has been in a holding mode on the most controversial and critical issues such as planning for the upcoming large auction of airwaves under acting Chairwoman Mignon Clyburn.
Wheeler, tapped to become the new permanent chairman, received a vote of approval from the Senate Commerce Committee on Tuesday, although Republican Senator Ted Cruz warned he might hold up Wheeler's confirmation until the nominee voices a more specific opinion on the power of the FCC over disclosure of political donors behind election TV ads.
The nomination of O'Rielly is expected to speed up the confirmation of Wheeler, an industry veteran who is an Obama fundraiser and adviser, and a former cable and wireless lobbyist.
O'Rielly has spent nearly two decades as a Republican staffer in Congress, most recently serving as a top aide to Senator John Cornyn of Texas. He has also advised former Senator John Sununu of New Hampshire and former House Commerce Committee Chairman Tom Bliley of Virginia on telecommunications issues.
Industry insiders, noting that much of O'Rielly's work has been done outside of the spotlight, described him as deeply knowledgeable about the issues he would address at the FCC thanks to years of experience on Capitol Hill. But several also chose the word "prickly" in talking about his personal style.
O'Rielly, who had in the past been on the short list for FCC commissioner, would join Ajit Pai as the second member of the Republican minority on the five-member panel, replacing former Commissioner Robert McDowell.
"The challenge for the next Republican commissioner is going to be trying to find the balance between being effective and shaping policy versus making a statement and laying the groundwork for a court appeal or congressional action," said McDowell, who is now at the Hudson Institute think tank.
"That always breeds a tension between principles and pragmatism and he will have to balance that." (Reporting by Jeff Mason and Alina Selyukh; Additional reporting by Douwe Miedema; Editing by Eric Walsh and Eric Beech)