President Obama gathered chief executives from energy, finance and technology companies to emphasize the threat posed by criminal and state-sponsored hackers, which the administration regards as one of the nation's main security challenges.

The White House meeting with corporate leaders including Honeywell's David Cote and JPMorgan Chase's (JPM) Jamie Dimon followed a warning from the top U.S. intelligence official that computer intrusions have moved past terrorism to become the top global threat and a report that six banks were hit by denial-of-service attacks.

"There is a consistent, persistent threat here that we need to be concerned about as a country," Cote said as he left the closed-door meeting with Obama and his advisers. "Just having this meeting, I think, was huge."

Dimon called the session "very helpful, productive."

The administration has been raising alarms that the nation's computer networks are vulnerable to hackers bent on stealing personal information and corporate secrets or interrupting vital industries such as energy, banking or transportation.

Obama issued an executive order Feb. 12 outlining policies for wider sharing of government data on hacking with companies, particularly operators of vital infrastructure such as power grids. The order directed the government to develop voluntary cybersecurity standards for those businesses and instructs U.S. agencies to consider adding the standards to existing rules.

James Clapper, the U.S. director of national intelligence, told the Senate Intelligence Committee yesterday that hostile hackers or an "isolated state" may succeed in breaching U.S. computer networks and disrupting power grids and other vital services in the next two years.

"What is absolutely true is that we have seen a steady ramping up of cybersecurity threats," Obama said in an interview on ABC's "Good Morning America" program broadcast today. "Some are state-sponsored," and "some are just sponsored by criminals."

Along with Cote and Dimon, the executives invited to the afternoon meeting included: Nicholas K. Akins, CEO of American Electric Power Company; Wesley G. Bush, CEO of Northrop Grumman; Clarence P. Cazalot Jr., chief executive of Marathon Oil; Exxon Mobil CEO Rex Tillerson; United Parcel Service CEO D. Scott Davis; David F. Melcher, chief executive of Exelis; Brian Moynihan, CEO of Bank of America; Eric Spiegel, CEO of Siemens; Randall Stephenson, CEO of AT&T; and Maggie Wilderotter, chief executive of Frontier Communications.

White House Chief of Staff Denis McDonough, National Economic Council Director Gene Sperling and Michael Daniel, Obama's cybersecurity coordinator, were among the White House officials also in the session, according to the invitation.

"Everybody is very interested in the idea of cyber security," Cote told reporters. "This is a great place for government and business to work together."

Administration officials have cited China as a source of cyber intrusions. Obama in the ABC interview said that the U.S. will "have some pretty tough talks with them" about the issue.

Multiple banks came under denial-of-service attacks yesterday, according to Carl Herberger, a vice president for the network security firm Radware in Tel-Aviv. While he declined to name them, JPMorgan spokesman Michael Fusco said an attack blocked the bank's website. Fusco said no customer data had been affected. The site has been restored to working order.

A group calling itself Izz ad-Din al-Qassam Cyber Fighters took responsibility for similar attacks on U.S. banks in December. Denial-of-service attacks flood Internet sites with traffic, blocking access. The group said in an online posting yesterday it would keep trying to disrupt banks, naming eight others as targets.

Separately, the Secret Service and the Federal Bureau of Investigation have begun looking into the posting of purported financial information of celebrities, government officials and first lady Michelle Obama.