WASHINGTON, Oct 3 (Reuters) - A prominent Democratic

U.S. senator called on a top regulator on Wednesday to impose

growth restrictions on Citigroup ( C/PN ) as the Wall Street bank

struggles to fix ongoing regulatory problems.

In a letter to Acting Comptroller of the Currency Michael

Hsu, Senator Elizabeth Warren said that Citi's years-long

struggle to fix data, controls and other management problems

show it has become "too big to manage" and should be curtailed.

A prominent bank critic who has previously taken aim at

Wells Fargo ( WFC ), JPMorgan ( JPM ) and others, Warren cannot

force Hsu to take action but her letter can still put pressure

on him to be tough on Citi, and draws more attention to the

bank's problems.

Reuters was the first to report the letter. Spokespersons

for Citi and the Office of the Comptroller of the Currency (OCC)

declined to comment.

Citi CEO Jane Fraser and other executives have previously

said that they are fully committed to complying with laws and

regulations and to addressing the bank's regulatory issues.

In 2020, the OCC and Federal Reserve fined Citi $400 million

and ordered the bank to draw up a plan to fix persistent risk

management and operational problems that had led to multiple

violations and penalties. The regulators again fined Citi in

July for failing to make enough headway on those problems.

Warren cited those consent orders, Citi's botched 2020

Revlon payment, as well as a July Reuters report that Citi

repeatedly breached a Fed rule that limits intercompany

transactions, in calling for Hsu to implement restrictions he

laid out in a 2023 speech about dealing with repeat offenders.

In that speech, Hsu said a restriction on growth, business

activities, capital actions, or some combination may be

warranted to incentivize a bank to fix its issues, although he

noted that such action would be a significant escalation.

"According to your own framework, it is clearly time to

protect the American financial system by imposing growth

restrictions on Citi," Warren wrote.

Bank regulators sometimes bar lenders with unresolved

regulatory and compliance issues from M&A deals and branch

openings, but more dramatic restrictions such as an asset cap

the Fed imposed on Wells Fargo ( WFC ) for its lapses are unusual.

(Reporting by Pete Schroeder; Editing by Michelle Price and

Muralikumar Anantharaman)