NEW YORK—Two former Wedbush Securities Inc. employees have been accused of providing client lists and other sensitive documents to one of the company's competitors, according to a lawsuit filed Thursday in New York State Supreme Court in Manhattan.

Wedbush, a New York-based financial services firm, claims a former managing director Louis Kerner and one of his subordinates, Michael Silverstein, abruptly left the company earlier this month for one of its rivals, Liquidnet Inc., also based in New York.

Before they left, the suit alleges, the two men emailed whole client lists and other proprietary documents to personal email accounts and tried to lock Wedbush managers out of their own databases by changing their passwords.

The lawsuit alleges Mr. Kerner informed his superiors on Oct. 16 that he and Mr. Silverstein were leaving for Liquidnet, just one day before exiting the firm. When his supervisor reminded him of his contractual confidentiality obligations, Mr. Kerner allegedly replied that all of his clients belonged to him, and that if the company objected it should contact his attorneys.

“The very next day, Kerner, Silverstein and Liquidnet began blatantly soliciting Wedbush's customers and potential customers using the trade secret customer data of Wedbush—a fact Wedbush only learned when its own affiliates and clients began forwarding these solicitations to Wedbush,” the suit claims.

In the lawsuit, Liquidnet and Mssrs. Kerner and Silverstein are all accused of breach of contract, misappropriation of trade secrets, unfair competition and unjust enrichment. Mssrs. Kerner and Silverstein also are accused of computer fraud and breach of fiduciary duty.

“The (Private Shares Group) customer data is the cornerstone of the PSG business, as it represents the source of PSG transactions from which all of its revenues are currently derived,” the suit claims. “Wedbush and PSG have invested substantial time, effort and expense in its creation, and Wedbush derives substantial economic value from preserving it as a trade secret.”

Wedbush has asked for a permanent injunction against all parties, as well as compensatory damages and any ill-gotten monetary gains resulting from the alleged crimes.

A spokeswoman for Liquidnet said the company is “reviewing the case” and declined further comment.