Officially, Brand's departure is not related to the controversies that have roiled the Department at the highest levels.
Ms. Brand is leaving to take a job in the private sector as general counsel, The Times reported.
In a statement, Brand said she is proud of the department's accomplishments during her short time there.
Rosenstein is the only person right now who is authorized to fire special counsel Robert Mueller, who is leading the investigation that has already brought down four former advisers to Trump, including former national security adviser Michael Flynn.
Steve Bannon will not testify before House committee in Russian Federation probe
Moscow has denied meddling in the US presidential election, and Trump denied any collusion between his associates and Moscow. Peter King, R-N.Y., also a member of the Intelligence Committee, at the Capitol in Washington, Tuesday, Feb. 6, 2018.
Brand's resignation was first reported by the New York Times. Just last week, Sessions praised both Brand and Rosenstein, noting that "they both represent the kind of quality and leadership that we want in the Department".
Rachel Brand, the third-ranking official at the Justice Department, is expected to resign Friday. That House Intelligence Committee memo contained serious allegations that Rosenstein, the FBI, and other authorities displayed damaging bias against President Trump that has been the impetus behind the Russian investigation.
'She felt this was an opportunity she couldn't turn down, ' Gorelick told the Associated Press. She has held politically appointed positions in the past three presidential administrations.
Trump also has criticized Sessions for recusing himself.
Brand, who now oversees the department's civil rights and antitrust divisions, has become embroiled in the scandal, as she is among a number of senior officials who urged Trump to not declassify the four-page memo, citing "grave concerns" about its accuracy. Speaking of FISA warrants - following the release of a memo that alleged the Federal Bureau of Investigation overstepped its bounds in using surveillance methods and that Rosenstein agreed to a FISA application to surveil Trump adviser Carter Page, Trump has implied he might fire Rosenstein.