President Bush tapped Cox earlier this month to replace SEC Chairman William Donaldson (search), who stepped down Thursday after two-and-a-half years at the agency.
If confirmed, Cox would fill a seat now held by Democratic Commissioner Harvey Goldschmid, who plans to return to teaching at Columbia University Law School this fall.
Thursday, the White House named SEC Commissioner Cynthia Glassman (search), the senior Republican on the SEC, to serve as acting SEC chairman until Cox arrives on the job.
Cox's nomination Thursday, after the financial markets closed, requires approval of the Senate, which will be in recess next week, returning July 11.
A confirmation hearing could occur sometime in July, although Democrats want to consider Cox in tandem with openings for two Democrats on the five-member Commission.
Senate Minority Leader Harry Reid, D-Nev., has recommended Bush give a second five-year term to SEC Commissioner Roel Campos, whose term has expired, and nominate SEC market regulation division director Annette Nazareth to replace Goldschmid.
Bush has been silent so far on which Democrats he will name to the SEC, and sent Cox's nomination to the Senate on its own.
"It would be our hope that we would have paperwork on all three vacancies at the SEC and consider them all together," said Senate Banking Committee spokesman Andrew Gray.
Campos and Nazareth didn't return phone calls seeking comment.
White House spokeswoman Erin Healy declined to comment on the administration's plans, saying: "We don't speculate on the timing of personnel announcements."