NEW YORK (Reuters) - An appeals court yesterday upheld the criminal convictions of former Tyco International Ltd. chief executive Dennis Kozlowski and former financial chief Mark Swartz, both of whom are serving prison terms for fraud.

The New York State Court of Appeals, in a written decision, rejected defence arguments that the former executives' trials were flawed and that the convictions should be reversed.

The men were found guilty of fraud, grand larceny and other charges by a Manhattan jury in 2005 after prosecutors said they stole more than $150 million from the Bermuda-based company. Kozlowski and Swartz have each served about three years of their prison terms, which were set at about eight to 25 years apiece. Kozlowski was also fined $70 million, and Swartz was fined $35 million.

The seven judges of appeals court, the state's highest, were unanimous in their decision.

Defence lawyers had argued that testimony by a key prosecution witness, a lawyer who conducted an internal investigation into Tyco's financial transactions, unfairly prejudiced the jury. They also contended that the trial court abused its authority by not allowing the defence access to certain documents prepared during the internal probe. Kozlowski, 61, was once one of the most powerful US chief executives. He became a symbol of corporate excess after prosecutors said he had used Tyco funds to throw lavish parties and buy accessories for his Manhattan apartment, including a $6,000 shower curtain and a $15,000 umbrella stand.

A lawyer for Kozlowski, John Martin, said his client had learned of the decision and "like me, he was disappointed".

A lawyer for Swartz, Nathaniel Marmur, said his client was also "very disappointed and we continue to believe firmly in his innocence. We are continuing to review our options."