Shares of RealD, a maker of 3-D imaging technology, plunged more than 20 percent Thursday morning after the company announced the evening before that Samsung Electronics had pulled out of a deal to make TV screens with RealD technology.

The Los Angeles company had talked up the Samsung agreement as a major step forward in market acceptance of its technology. In May, the company issued a statement that Samsung planned to develop 23-inch and 27-inch computer monitors and 55-inch TV screens through a license agreement.

In a conference call, RealD Chief Executive Michael Lewis said he remains bullish on its technology and plans to get it into the marketplace despite any setbacks.

Shares of RealD traded at $8.80, a loss of $2.46 or 22 percent by mid-day Thursday.