At least seven law firms are pursuing class-action lawsuits against GT Solar (NSDQ: SOLR) as the company’s shares trade 35.5 percent below an initial offering price of $16.50 per share.

Coughlin Stoia Geller Rudman & Robbins announced the first suit Friday afternoon, which was quickly followed by suits from Federman & Sherwood, The Brualdi Law Firm, Shapiro Haber & Urmy, Kahn Gauthier Swick, Abraham, Fruchter & Twersky and Brower Piven.

The day after GT Solar’s IPO, which was less than two weeks ago, one of its customers, LDK Solar, announced a contract to buy silicon ingot furnaces from another company, JYT Corp.

Silicon ingot furnaces for LDK represented less than 8 percent of GT Solar’s backlog, according to a company statement, but that didn’t stop shares from falling 13.7 percent on top of a drop of 11.6 percent the previous day (see GT Solar Sinks on LDK News, GT Solar Goes Public and Green Light: Was the GT Solar IPO a Hit Job?).

The Kahn Gauthier Swick, Coughlin Storia Geller Rudman & Robbins and Brower Piven announcements claim that GT Solar “failed to disclose the extent of risk” surrounding its business relationship with LDK Solar.

The Coughlin Stoia Geller Rudman & Robbins release adds more detail, saying that the company didn’t disclose the “imminent risk of losing out on a contract for future orders from LDK due to delays in shipping production equipment to LDK.”

And the Federman & Sherwood complaint alleges “a series of material misrepresentations … which had the effect of artificially inflating the market price.”

The other three announcements were more vague, but also mention the LDK announcement the day after GT Solar’s IPO.

All of the firms are still looking for lead plaintiffs, according to the press releases.

The lawsuits aren’t exactly unexpected. The day of the LDK announcement, Prometheus Institute President Travis Bradford said he wouldn’t be surprised if investors questioned whether GT Solar knew about the deal in advance, and lawyers often enter the picture whenever public shares fall steeply (see posts from The D&O Diary here, here and here).

Some of the same firms involved in the GT Solar lawsuits filed class-action suits against LDK Solar and China Sunergy in October (see LDK Rises Despite Class-Action Threat and China Sunergy’s Troubles Continue).

The suits against LDK have been combined into a single consolidated class-action lawsuit. The Stanford Law School Securities Class Action Clearinghouse indicates that suits against both companies are still pending (see updates about the lawsuits, as well the legal firms named in the complaints, on the clearinghouse’s LDK page here and Sunergy page here).

In recent trading, GT Solar shares fell 10.4 percent to $10.64 per share.