The company predicted revenue of $65 million to $75 million for the year, compared with a prior forecast of $80 million to $85 million. Analysts polled by Thomson Financial expect revenue of $80.3 million for the company's fiscal year ending in March 2008.

"Based upon recent discussions with our distribution partners, we believe that we will gain regulatory approvals to market the full Micrus product line in China and to expand our current product offering in Japan to include our stretch-resistant and Cerecyte microcoils. However, we believe that the timing of these approvals will be later than we had anticipated," John Kilcoyne, Micrus president and chief executive, said in a statement.

Micrus said it doesn't expect to recognize revenue from China in the current fiscal year. The company had previously factored $7 million of Chinese revenue into its guidance for the year.

The company also noted revenue in North America has been weaker than expected.

Micrus shares fell $1.08, or 4.6 percent, to $22.49 in aftermarket activity. Earlier, shares added 39 cents to end regular trading at $23.57.