Trading in shares of Seattle-based L&L Energy was halted by Nasdaq before the market opened Monday, without an explanation from either party.

In a brief statement, the market operator said only that “trading will remain halted until L&L Energy Inc. has fully satisfied Nasdaq’s request for additional information.”

L&L, which operates coal mines in China, was the subject of a lengthy report in September by a firm that had shorted its stock.

The firm, GeoInvesting, alleged L&L has falsely claimed ownership of some properties and was “booking substantial revenue from operations that have been idled for quite some time.”

That allegation sent the stock plunging about 40 percent on Sept. 20, though it has recovered slightly.

L&L has denied any impropriety and appointed a committee of independent directors and an outside law firm to investigate the claims. Last week, it said it provided the investigators with “detailed repudiation” of GeoInvesting’s claims.

In a September interview, GeoInvesting co-founder Dan David said he would share the firm’s documentation for its allegations with officials at the Securities and Exchange Commission and Nasdaq.

Nasdaq issued about 20 trading halts Monday, but most lasted only five minutes to allow some market-moving news about the subject company to be released.

The halt on L&L was the only one Monday classified as a T12, “trading halted for information requested by Nasdaq.”

That designation was used eight other times in the past three months; all were issued on the day before closing on a previously announced purchase of the subject company. No such purchase of L&L has been announced. The company did not respond to a request for comment.

Rami Grunbaum: 206-464-8541 or rgrunbaum@seattletimes.com