May 24 (Reuters) - An internal watchdog investigating workplace culture at the U.S. Federal Deposit Insurance Corporation was not informed in a timely manner of misconduct allegations involving senior agency officials, the agency said in a memo released Friday.

FDIC Chair Martin Gruenberg this week offered to step down under pressure from lawmakers who cited the results of an independent investigation into sexual harassment and other misconduct.

The watchdog office, which is also conducting an investigation, "learned of several allegations of misconduct regarding senior FDIC officials that were not reported...in a timely manner," Inspector General Jennifer Fain said in a memo addressed to Gruenberg dated Thursday.

She added that her office was now reviewing the allegations to determine how they should be incorporated into their work. (Reporting by Douglas Gillison, Editing by Franklin Paul)