Intel Corp. agreed to buy McAfee Inc. for $7.68 billion, its biggest-ever acquisition, adding security software to its chipmaking arsenal.

McAfee investors will receive $48 a share in cash, Santa Clara, California-based Intel, the world’s largest chipmaker, said in a statement today. That’s 60 percent more than McAfee’s closing price yesterday. Both boards have unanimously approved the deal, Intel said.

The acquisition of McAfee, which trails Symantec Corp. in security software, will give Intel an advantage over other chip companies that must use outside security programs, said Hans Mosesmann, an analyst at Raymond James Associates in St. Petersburg, Florida. The deal also helps Intel expand beyond PCs as Chief Executive Officer Paul Otellini is trying to break into mobile handsets and grow in other portable devices.

“Their ability to be successful in the non-PC market, and even in the PC market, is going to depend more on system solutions, and security is becoming a really big deal,” said Mosesmann. “The security threats that are out there are not going away -- you could argue that they are going to get worse - - and having a tightly coupled hardware and software is a strategic advantage.”