NEW YORK (CNN/Money) - Trying to move beyond a difficult past, Tyco International Ltd. named a chief executive officer Thursday to replace a CEO who resigned just days before his indictment.

The Bermuda-based manufacturing conglomerate said its board had chosen former Motorola Inc. (MOT: Research, Estimates) president and chief operating officer Edward Breen. He takes over from Dennis Kozlowski, who resigned in June before being indicted for sales tax evasion.

The surprising news sent shares of Tyco (TYC: Research, Estimates) surging $2.50, or 30 percent, to $10.75 after hours following a big tumble in the regular session. But Motorola (MOT: Research, Estimates) stock slipped $1.58, or 13 percent, to $10.60, in after-hours trading.

"Ed has a superb record of tackling very difficult and complex business challenges, creating effective strategies and methodically executing on his plans," John F. Fort, Tyco's lead director said in a statement.

About an hour before the CEO announcement, Tyco wrapped up a conference call in which it denied bankruptcy rumors. In the call, the company also said it had made no progress in its search for a new CEO.

The Breen news "came right out of space," Steve Altman, a credit analyst for Commerzbank Securities, told Reuters. "That was the last thing I was expecting to hear this afternoon. Preliminarily, I think it's fantastic."

The change comes during a difficult time for the company which makes everything from fire-detection systems and circuit boards to disposable medical supplies and undersea cables.

Tyco shares tumbled nearly 18 percent in regular trading Thursday, widening its year-to-date loss to more than 84 percent.

The rumors about financial collapse are just the latest problem for Tyco, which has been hammered by investor worries that the company is hiding something behind it complicated accounting.

Tyco has never restated results, but the Manhattan District Attorney and the SEC are investigating whether company funds were improperly used to enrich executives.

In the statement, Fort tried to distance the company from that cloud, saying Breen demands "the highest standards of corporate conduct."

"His personal and professional integrity are unassailable," Fort said.

Kozlowski, who is credited with building Tyco's business in the 1990s through a series of acquisitions, resigned just before a criminal indictment on tax evasion charges.

To replace Breen, Motorola named Mike Zafirovski, who was executive vice president and president of Motorola's personal communications sector.

Tyco this week reported third-quarter earnings of $900.5 million, or 45 cents a share, from continuing operations excluding special items for the period ended June 30. That was down from the $1.3 billion, or 73 cents a share, it earned on the same basis in the year-earlier period.