(Reuters) - Below are people mentioned as contenders for senior roles as U.S. President-elect Donald Trump works to form his administration before taking office on Jan. 20, according to Reuters sources and media reports. Trump has already tapped a number of people for other top jobs in his administration. For a list of posts already filled, see. * Mitt Romney, 2012 Republican presidential nominee and former Massachusetts governor  * Rudy Giuliani, Republican former mayor of New York City * Bob Corker, Republican U.S. senator from Tennessee and chairman of the Senate Foreign Relations Committee * David Petraeus, retired general and former CIA director who pleaded guilty to mishandling classified information that he shared with his biographer, with whom he was having an affair * Jon Huntsman, former Republican Utah governor and ambassador to China under President Barack Obama, ran for Republican presidential nomination in 2012  * James Stavridis, retired Navy admiral * John Bolton, U.S. ambassador to the United Nations under President George W. Bush, foreign policy adviser to 2012 Republican presidential nominee Mitt Romney * Rex Tillerson, president and chief executive officer of Exxon Mobil * Joe Manchin, Democratic U.S. senator for West Virginia  * Dana Rohrabacher, Republican U.S. representative of California and senior member of the House Committee on Foreign Affairs * Michael McCaul, Republican U.S. representative from Texas and chairman of the House Homeland Security Committee * David Clarke, Milwaukee County sheriff and vocal Trump supporter * Retired Marine Corps General John Kelly, former leader of the military’s Southern Command  * Joe Arpaio, who lost his bid for re-election as Maricopa County, Arizona sheriff, and has campaigned for Trump * Kris Kobach, Kansas secretary of state * Frances Townsend, who was homeland security and counterterrorism adviser to President George W. Bush * Jeff Holmstead, energy lawyer, former EPA official during George W. Bush administration * Robert Grady, venture capitalist, partner in private equity firm Gryphon Investors  * Leslie Rutledge, Republican Arkansas attorney general * Carol Comer, commissioner of the Indiana Department of Environmental Management * Scott Pruitt, Republican Oklahoma attorney general * Kevin Cramer, Republican U.S. representative from North Dakota * Robert Grady, venture capitalist, partner in private equity firm Gryphon Investors  * Heidi Heitkamp, Democratic U.S. senator from North Dakota * Joe Manchin, Democratic U.S. senator from West Virginia * Gary Cohn, president of Goldman Sachs Group Inc * Larry Nichols, co-founder of Devon Energy Corp * James Connaughton, CEO of Nautilus Data Technologies and a former environmental adviser to President George W. Bush * Rick Perry, Republican former Texas governor * Forrest Lucas, founder of oil products company Lucas Oil * Heidi Heitkamp, Democratic U.S. senator from North Dakota * Robert Grady, venture capitalist, partner in Gryphon * Cathy McMorris Rodgers, U.S. representative from Washington state and House Republican Conference chair * Sarah Palin, former Alaska governor and 2008 Republican vice presidential nominee * Jan Brewer, former Republican Arizona governor * Mary Fallin, Republican Oklahoma governor * Ray Washburne, CEO of investment company Charter Holdings * Navy Admiral Mike Rogers, director of the National Security Agency * Ronald Burgess, retired U.S. Army lieutenant general and former Defense Intelligence Agency chief  * Robert Cardillo, director of the National Geospatial-Intelligence Agency * Pete Hoekstra, Republican former U.S. representative from Michigan * Rudy Giuliani, former New York mayor   * Debra Wong Yang, former U.S. attorney for California’s Central District, appointed by former President George W. Bush * Ralph Ferrara, a securities attorney at Proskauer * Paul Atkins, Republican former SEC commissioner Paul Atkins who is heading Trump’s transition team for independent financial regulatory agencies, including the SEC * Daniel Gallagher, Republican former SEC commissioner * John Allison, a former CEO of regional bank BB&T and former CEO of the Cato Institute * Paul Atkins, former SEC commissioner  * Thomas Hoenig, Federal Deposit Insurance Corp vice chairman  * Dan DiMicco, former CEO of steel producer Nucor Corp * Robert Lighthizer, a Washington trade attorney and former deputy U.S. trade representative during the Republican Reagan administration * Andrew Puzder, CEO of CKE Restaurants  * Lou Barletta, Republican U.S. representative from Pennsylvania * Victoria Lipnic, U.S. Equal Employment Opportunity Commission member and former Labor Department official during the George W. Bush administration * Gary Cohn, Goldman Sachs Group Inc president * Mick Mulvaney, Republican U.S. representative from South Carolina * David Malpass, former chief economist with investment bank Bear Stearns and a senior Trump adviser who also served in the Ronald Reagan and George H.W. Bush presidential administrations  * Scott Brown, former Republican U.S. senator from Massachusetts * Sarah Palin, former Alaska governor * Jeff Miller, former Republican U.S. representative from Florida who was chairman of the House Veterans Affairs Committee The Trump transition team confirmed the president-elect would choose from a list of 21 names he drew up during his campaign, including Republican U.S. Senator Mike Lee of Utah and William Pryor, a federal judge with the 11th U.S. Circuit Court of Appeals.  
Factbox: Contenders for key jobs in Trump's administration