Shares of medical firm American Medical Systems Holdings, Inc. (NASDAQ: AMMD) plunged nearly 18 percent on Wednesday after the firm lowered its expectations for first quarter revenue.

Shares of the firm dropped $3.48, or 17.95 percent to $17.95 in afternoon trading on the Nasdaq Stock Market.

On Tuesday the Minnetonka, Minn.-based firm reported preliminary sales of $108.4 million and earnings of 5 cents to 7 cents for the first quarter of 2007, which ended March 31. The Company had previously provided revenue guidance for the quarter of $113 to $118 million.

Analysts polled by Thomson Financial had expected 14 cents earnings per share. The company had previously predicted earnings per share to be in the range of 13 cents to 15 cents.

This quarter, vendor quality issues, combined with performance shortfalls in our internal manufacturing and demand planning efforts, resulted in an inability to consistently meet demand for several key product lines, said president and chief executive Martin Emerson in a statement.

The company said its men’s health business grew 5 percent for the quarter, excluding an item, but was hindered by product availability issues. Its women’s health business grew 20 percent although it did experience some vendor-related supply issues.

American Medical is a supplier of medical devices and procedures to cure erectile dysfunction, benign prostatic hyperplasia, incontinence, menorrhagia, prolapse and other pelvic disorders in men and women.