Kozlowski, 58 and Mark Swartz, 44, both face up to 25 years in prison on the counts of grand larceny alone.
After nearly 11 days of deliberations, the jury reached its verdict.
The defendants were found guilty of taking nearly US$600m (A$777m) from the US industrial products and services company.
“We are very disappointed,” Kozlowski’s lawyer Stephen Kaufman said.
“But I can assure you we are appealing the verdict… and we look forward to that appeal and we have confidence in that appeal,” he added.
Swartz’s lawyer professed his client’s innocence.
“There is no doubt in my mind that he never stole a cent,” lawyer Charles Stillman told reporters.
Prosecutors charged the pair with stealing US$150m from Tyco and procuring a further US$430 million by overtly selling shares while artificially inflating the company’s stock value.
Kozlowski was sacked from Tyco on June 3, 2002, after the company was forced to restate its results to show a multi-billion dollar loss.
The case has become synonymous with America’s other major corporate scandals, namely Enron and WorldCom, in representing the upper end of rampant business greed.
A first trial detailed alleged misuse of company funds to purchase items such as a US$15,000 ‘dog umbrella stand’ and a US$6,000 shower curtain.
The judge ordered a mistrial in April 2004, citing ‘outside pressure’ on the jury.
The second trial offered less sensational evidence after criticism of both the prosecution and the defence’s handling of their cases.
Kozlowski and Swartz have been allowed to remain free on bail before sentencing which has been tentatively set for August 2.