Shares of Stratasys Ltd. plunged 28 percent Tuesday after the maker of 3-D printers warned of a loss for fiscal 2014 and announced a new earnings guidance for 2015 that broadly missed Wall Street ­expectations.

Investors pounded the stock. It fell $22.72 a share to close at $57.36, a level not seen since 2012.

Company officials could not be reached for comment.

The Eden Prairie-based manufacturer issued a "preliminary" announcement late Monday saying it expects sales to jump 54 percent to $748 million in 2014. Stratasys also expects to post a loss of $116 million to $129 million, or $2.32 to $2.58 a share, for the year.

The loss includes a surprise $100 million "goodwill impairment charge" that the company took in December relating to its MakerBot consumer printer business. Stratasys bought MakerBot in 2013 for $400 million. The charge may exceed MakerBot's estimated annual revenue.

The company said in a statement that MakerBot now represents roughly 12 percent of Stratasys' sales. In a statement, Stratasys officials said they do "not expect this accounting write-down to affect its ongoing business or future financial performance."

Investors were not pleased by the charge or company assurances that the charge is largely an accounting move.

Even without the MakerBot charge, Stratasys missed analysts' expectations. The company said that without the charge, fiscal 2014 earnings reached $102 million to $105 million, or $1.97 to $2.03 million a share.

Analysts expected 2014 sales of $763 million and earnings of $2.25 per share.

For 2015, Stratasys forecast sales of $940 million to $960 million and adjusted earnings of at least $109 million to $118 million, or $2.07 to $2.24 a share. Analysts had expected $2.59 a share.

The steep decline prompted New Jersey law firm Bronstein, Gewirtz & Grossman to start an investigation. Peretz Bronstein said in a statement late Tuesday that he was investigating whether Stratasys may have violated SEC regulations by misleading shareholders about MakerBot and failing to warn them about potential losses sooner.

Bronstein, who asked worried investors to contact his firm, complained that ­Stratasys boasted at the time it bought the company in 2013 because of "MakerBot's rapid adoption by designers and engineers." The CEO "called it the 'strongest brand in the desktop 3-D printer category.' "

Company officials acknowledged MakerBot's "slower growth" during the fourth quarter. But they defended their broader plans for growth. Going forward, they intend to crank up expenses associated with long-term growth in an effort to snatch market share in a fast-growing industry, CEO David Reis told analysts during a call Tuesday.

Stratasys expenses will grow by 2 percent of revenue this year as it beefs up sales, marketing, new products and infrastructure.

Reis said Stratasys is entering a "new phase of increased investment in its business" because more manufacturers are adopting 3-D printing into their factories. Stratasys wants to be ready to meet the increased demand, he said.

"The investment plan is designed to implement broad product development and infrastructure which would support annual revenues of $3 billion in 2020," the company said in a statement.

Its crushed stock is an anomaly for a company that has been a long time Wall Street favorite due to its rocket-like growth, strategic acquisitions and diversified products.

It now makes 3-D printers for consumers and markets them through such big name retailers as Home Depot, Staples and Amazon. At the same time, it has expanded its global contract manufacturing business for factory customers and acquired several commercial 3-D printer manufacturers.

Dee DePass • 612-673-7725