The Jakarta high court based its verdict on that of a district court which last year found him guilty of misusing millions of dollars of state funds.
"
In my opinion I have done nothing wrong
"
Akbar Tandjung
Mr Tandjung, who is also leader of the former ruling Golkar party, will now take his appeal to the country's Supreme Court.
Despite last year's verdict Mr Tandjung has retained his official posts and not gone to jail.
He is expected to remain a free man until his Supreme Court appeal is heard, a process that could take another year.
Mr Tandjung is one of several high-profile figures whose trials have been closely watched after President Megawati vowed to crack down on corruption.
The case is particularly complicated because Golkar is part of Megawati's governing alliance, and Mr Tandjung has been seen as a potential candidate in presidential elections due in 2004.
Mr Tandjung, who has denied all charges, was not at the High Court to hear the ruling.
But speaking to reporters later at parliament he said he was disappointed by the decision.
"In my opinion I have done nothing wrong. As a man who wanted to be proven innocent, of course I am," he said.
Party funding
The judge, Ridwan Nasution, said Mr Tandjung's conviction was found to be "legal and convincing".
The convictions of two other defendants were also reported to have been upheld.
Two co-defendants, Dadang Sukandar and Winfried Simatupang, who ran the foundation responsible for distributing the food aid, also had their convictions upheld.
Their sentences were doubled from 18 months in prison to three years.
Mr Tandjung was convicted of diverting $4.5m of government funds while he was a cabinet secretary.
The money was meant to pay for food packages for victims of the 1998 Asian financial collapse.
The BBC's Jakarta correspondent says it is still not clear what actually happened to the money but it is widely believed to have been used to help finance the Golkar party's election campaign in 1999.