IBM on Thursday unveiled a new mainframe computer called zEnterprise, which it said was the most powerful mainframe ever and is more cost-efficient than previous-generation products.

The move comes as International Business Machines Corp seeks to secure its market leadership in mainframes, which are powerful computers used by large corporations to process high volumes of data and financial transactions.

IBM and its main rivals, Hewlett-Packard Co and Oracle Corp, are all targeting corporate data centers, which are struggling to deal with heavy data traffic and seeking ways to lower the costs of running such systems.

Even Cisco Systems Inc, traditionally a maker of routers and switches, recently began selling data center servers, promising simpler and more energy-efficient systems.

IBM said its zEnterprise is 40 percent to 60 percent faster than its predecessor, System z10, but uses about the same amount of electricity.

Tom Rosamilia, head of IBM's System z mainframe business, said that over 40 percent of chief information officers, who make technology purchasing decisions, expect their data centers to hit space or power constraints within a year and a half.

The moment when you hit the capacity when you have to build another data center, or the power company says you can't have any more, then capacity at the margin becomes very, very expensive, he told Reuters.

The zEnterprise really helps them to reduce their footprint so they can avoid building out a new data center for real estate or power reasons, he said.

The Armonk, New York-based company did not disclose the price of the product, but said its price relative to capacity would be lower than for the z10.

While IBM has been shifting its focus to services and software and away from commoditized hardware, high-end servers are still crucial as it tries to sell a wide portfolio of technology services and products.

It said it spent $1.5 billion on research and development for the zEnterprise system in a 4-year project involving over 5,000 of its employees.

The upgrade was well-flagged. Sales of the System z series, including the z10 and earlier products, fell 24 percent year-on-year in the second quarter as customers awaited the launch.

The core server in the zEnterprise system contains the world's fastest, most powerful microprocessors. They run at 5.2Ghz, making them capable of executing more than 50 billion instructions per second.

The microprocessor technology also includes new software to help handle data-heavy workloads, by utilizing predictive analytics technology, it said.

The company also said the new mainframes could be integrated with other IBM servers, using IBM's blade products and software.

It will also come with a water cooling option, which could help reduce energy consumption by up to 12 percent by removing air heat, it said.

(Reporting by Ritsuko Ando; Editing by Richard Chang)