Global Payments on Monday said that Visa has dropped the US-based payment processor after data from as many as 1.5 million credit cards was looted from its system.

The word came as credit card titans Visa and MasterCard scrambled to thwart cyber crooks who snatched a massive trove of valuable account data.

The card industry was jolted by news last week that data from as many as 10 million cards was stolen.

Global Payments said however that "less that 1.5 million accounts" in North America were hit by "unauthorized access" to its processing system.

Information stolen was from credit card magnetic strip "tracks" known to include credit card numbers, verification codes, and expiration dates.

"The investigation to date has revealed that Track Two card data may have been stolen, but that cardholder names, addresses and social security numbers were not obtained by the criminals," Global Payments said in a release.

"Based on the forensic analysis to date, network monitoring and additional security measures, the company believes that this incident is contained."

Global Payments chief executive Paul Garcia said in a conference call that the company was still processing Visa transactions and expected to regain its trusted status after fixing compliance issues.

Analysts said they were awaiting more news from the latest breach.

"Sounds like there's a lot more going on out there than the payment industry and law enforcement have nailed down and are prepared to talk about," said Gartner analyst Avivah Litan.

Aspects of the breach at Global Payments differed from details released last week by Visa regarding a massive theft of digital account information, according to the analyst.

"Their breach seems to be very different than the one Visa issued an alert on," Litan said.

Visa and MasterCard last week both said they were investigating the theft of information from a "third party" and stressed that their internal networks had not been cracked.

Litan said that industry sources revealed that numbers from more than 10 million credit card accounts were stolen in the breach, with the entry point being a New York City taxi and parking garage company.

The thieves stockpiled stolen credit card numbers for months before beginning to use them, according to the analyst.

Indications were that the culprits were part of a Central American crime gang, Litan told AFP.

Alerts sent to banks warned that sufficient account details were stolen to make counterfeit credit cards.

People should alert card issuers to suspicious account activity, according to Visa and MasterCard.

"Individual hackers and cybercrime organizations focus on environments that are ripe with valuable data and are lacking in security controls -- many payment processors fit this model," said McAfee computer security strategist Brian Contos.

"Attacks targeting credit cards... are relatively persistent for the simple fact that credit card data is valuable and more easily converted into cash than, say, stolen intellectual property."

Contos said that stealing credit card information is so common that there is "oversaturation of black markets" and cyber crime gangs are warehousing data in the hope prices rise for swiped account information.

"Why get two dollars a card when you might get $10 in a few months?" he asked rhetorically.

"In many of these cases, it is likely that nobody is aware that those credit cards have been compromised."