* Deadline for comment letters on Nasdaq plan is Wednesday
* Citadel bought/sold over $3.8 bln of Facebook stock during IPO
By John McCrank
NEW YORK, Aug 21 (Reuters) - Citadel LLC urged U.S. regulators to approve Nasdaq OMX Group's $62 million compensation plan for firms harmed by Facebook's May 18 glitch-ridden initial public offering.
Citadel's market making unit bought and sold over $3.8 billion worth of Facebook stock during the IPO and "incurred losses protecting retail investors from the problems caused by Nasdaq," the firm said in a letter on Tuesday to the Securities and Exchange Commission.
Nasdaq filed its all-cash plan with SEC in July.
Regulations cap the exchange's liability at $3 million a month for problems caused by technology issues, and the Facebook accommodation plan would temporarily raise that amount, though not to a level anywhere near the upward of $500 million lost by the major retail market makers in the IPO.
"While the extent of exchange immunity from liability for mishandling orders is an important and complex public policy issue, we submit that any commission consideration of this issue should be addressed at a later time," Citadel said.
Citadel lost around $30 million due to the IPO, a person familiar with the situation previously told Reuters.
Wednesday is the deadline for interested parties to submit comment letters to the SEC on Nasdaq's proposal.
The other top retail market makers involved in the IPO were Swiss bank UBS AG, Knight Capital Group, and Citigroup's Automated Trading Desk.
UBS said it lost more than $350 million when the lack of timely order confirmations by Nasdaq caused UBS's internal systems to re-enter orders multiple times.
A spokeswoman for UBS, which has said it may take legal actions against Nasdaq to recover the full extent of its losses, said the firm had no comment.
Knight said it lost $35.4 million due the IPO. A spokeswoman at Knight said it is still unclear as to whether the firm will formally comment on Nasdaq's reimbursement plan. A source familiar with the firm's plans told Reuters Knight is likely to accept Nasdaq's offer.
A spokesman for Citi, which sources have said lost around $30 million, could not confirm if the firm would submit a comment letter.
The all-cash $62 million reimbursement plan is $22 million larger than Nasdaq originally proposed. The prior proposal was made up mostly of trading rebates, which drew loud protests from other exchanges and market makers.
A Nasdaq spokesman could not immediately be reached for comment. Spokesmen for New York Stock Exchange operator, NYSE Euronext, and No. 3 U.S. equities exchange, BATS, said their companies did not plan to file comment letters with the SEC. A spokesman for No. 4 exchange, Direct Edge, was not immediately available for comment.
In a regulatory filing on Aug. 3, Nasdaq said it is the subject an investigation by the SEC, as well as eight lawsuits by investors and one by trading firms, for its role in Facebook's problematic debut.
While Nasdaq said it believes the lawsuits are without merit, it said it expects "to incur significant additional expenses in defending the lawsuits, in connection with the SEC investigation and in implementing technical changes and remedial measures which may be necessary or advisable."