ST. PAUL — Gov. Mark Dayton on Thursday picked a trusted aide to oversee construction of a new, $975 million stadium for the Minnesota Vikings, the signature legislative accomplishment of his term so far.

Dayton named deputy chief of staff Michele Kelm-Helgen to lead the Minnesota Sports Facilities Authority, a five-member panel charged with keeping tabs on a public investment of nearly $500 million. The group will oversee design and construction and operate the 65,000-seat downtown Minneapolis stadium for uses ranging from concerts to high school sports events.

Kelm-Helgen worked on Dayton’s campaign and joined his administration when he took office in January 2011. She was previously lead adviser to former Democratic Senate Majority Leader Larry Pogemiller and has also worked as a partner at a lobbying firm and a director at Control Data Corp.

In a conference call with reporters, Kelm-Helgen said she was “surprised, thrilled and daunted” by the appointment.

“I am very committed to making sure the stadium is built within budget and on time and provides the kind of job opportunities for Minnesotans that we have been so excited about,” she said.

Kelm-Helgen said she intends to convene the authority as early as next week to begin working out details — ranging from decisions as small as office space and as large as whether to manage the construction project or give that role to the Vikings. The group will also hire an executive director.

The governor’s chief of staff, Tina Smith, said Dayton trusts Kelm-Helgen’s ability to keep the project on time and on budget. Smith spoke for the governor, who is on a trade mission in China.

“She can read a spreadsheet faster than anyone I know,” Smith said of Kelm-Helgen.

Dayton also named John Griffith, Target Corp.’s executive vice president for property development, and Duane Benson, a former state senator and professional NFL player, to the authority. Benson played for the Oakland Raiders, Atlanta Falcons and Houston Oilers.

Minneapolis Mayor R.T. Rybak chose Dr. Barbara Butts Williams, a dean at Capella University with a business and higher education background, and Minneapolis Regional Labor Federation president Bill McCarthy. Butts Williams’ husband, Dr. John Williams, is a former NFL player who played for the Los Angeles Rams and Baltimore Colts.

The stadium law required Dayton to pick three members, including the chairperson, and Rybak to choose two.