Shalres in telecom gear manufacturer Tekelec plummted more than 15 percent on Friday after Chief Executive Officer Fred Lax said he was leaving the company.

Tekelec (Nasdaq: TKLC) is in the process of moving its headquarters to Morrisville from California. Lax cited personal reasons for not wanting to move east. He has been with the firm for five years.

Lax’ decision, which was announced on Thursday, led to a 15.6 percent drop in Tekelec’s stock on Friday. It closed down $2.54 at $13.68.

Trading was exceptionally heavy. More than 7.7 million shares traded hands. Its regular daily trade volume as reported by Nasdaq is under 800,000 shares.

Lax’ resignation will take effect as of Jan. 1, 2006. By that time, the company said its headquarters move should be complete. Tekelec said in a statement that it has launched a search for a replacement.

“When Tekelec completes the transition of its corporate headquarters to North Carolina and closes its California office at the end of 2005, I will not move with the Company,” Lax said in a statement. “I have decided, for personal reasons, to stay in California and pursue other opportunities. I have very much enjoyed the past five years with Tekelec and am proud of the Company’s accomplishments. I believe Tekelec is well positioned as a market leader in signaling and continues to strengthen its position globally in next-generation switching and communication software solutions.”

Tekelec’s shares recently traded at more than $20 a share. The stock’s 52-week high of $26.13 was reached a year ago in November.

Its 52-week low is $11.77, a point reached in May.