Acsa operations director Bongani Maseko told the company's results presentation in Johannesburg: "Prior to changing the ramp handling company, we had 24-34 bags tampered with per day at OR Tambo - but now it ranges from 6-8 bags," he said.
The airport handled 24 000 bags each day, and R250 000 was being spent per month on baggage protection for OR Tambo.
"With the new ramp handlers, their contracts speak directly to baggage pilfering," Maseko said.
Addressing security issues, he said Acsa worked closely with the SA police.
"We've seen a decrease in crime at all our airports due to the increased presence of police," he said.
The airports operator on Thursday reported what it termed "good" results.
For the year ended March 31 2008, it had seen an increase in departing passenger volumes.
Departing passenger volumes were up by 10.6% to 18.2 million - and this was "despite a difficult operating and economic regulatory environment", the company said.
Revenue for the period under revue rose by nine percent to R2.797bn, while commercial and other non-aeronautical revenues grew by 20.2% to R1.429bn.
Infrastructure investment increased by a whopping 215% to R5.2bn with R1.703bn being spent on OR Tambo International, R603m at Cape Town International, R1.925bn at the new green field airport development at La Mercy and Durban International, and R298m at South Africa's domestic airports.