Jagannathan spoke to Computerworld UK at Oracle OpenWorld this week in San Francisco, where he was giving a talk on Citi's implementation of Oracle's Siebel CRM application.
Citi has 4,400 Siebel users, across 93 countries, and deals with 5 million analytic queries a month, as well as 300,000 deals and 60,000 call reports. Citi is currently using Siebel 8.1, but does upgrades every 24 months.
However, Jagannathan told Computerworld UK that due to increasing compliance concerns in the financial services industry, which vary in complexity across the globe, Oracle's public cloud is a no-go for Citi.
"Given the global nature of our business, combined with data privacy and regulation concerns, we are tied up quite a bit. Cloud is pretty challenging," he said.
"We did consider it, but because we store both customer and transactional data, it would be a challenge in several of the markets we operate in.
He added: "We really don't think cloud can satisfy most of our offerings."
Oracle has unveiled a number of public cloud offerings in recent months, the latest of which includes infrastructure-as-a-service, to go along with its platform-as-a-service and Fusion application products.
"The fundamental architecture of cloud computing is really a utility model that has been with us for 100 years or more," Oracle CEO during his keynote.
"It looks exactly like the architecture of an electric utility. All of this is enormous, capital intensive stuff but it's managed by the electric utility and provided to the consumer as a service. The user simply plugs in to get it. All the capital costs are borne by the utility."
He added: "We decided to get into cloud computing back in 2004, when we started our Fusion Applications project," he added. "It took us a long time to build a suite of cloud applications and the underlying suite for those applications. We had to build the platform first before we could really build the CRM applications that run in the cloud, the HCM applications that run in the cloud."