UPDATE 1-Virtu sues U.S. SEC securities regulator over records request

(Updates throughout with details, background)

Nov 29 (Reuters) - Virtu Financial Inc on Tuesday said it has sued the U.S. Securities and Exchange Commission, alleging the regulator failed to respond to the market maker's public records request.

Virtu said it submitted a request through the Freedom of Information Act (FOIA) in June to determine if the SEC had met legal requirements to evaluate potential investor harm and market risks while weighing new rules for retail stock order handling and execution.

The SEC did not immediately respond to a request for comment.

Agencies are required by law to respond to a FOIA request within twenty days, but the law does not require agencies provide all responsive documents within that time frame. Such document requests do not always yield substantive responses and can have lengthy waiting periods.

The SEC under Democratic chair Gary Gensler has come under scrutiny from Republican lawmakers and industry for what they describe as an aggressive and sweeping overhaul of existing rules and shortened time lines for public comment. (Reporting by Chris Prentice in New York and Niket Nishant in Bengaluru; Editing by Saumyadeb Chakrabarty and Alexander Smith)