For Electronic Data Systems Corp., it’s back into the arms of a larger corporate parent.

Under the terms of a definitive agreement announced today, Hewlett-Packard Co. will buy the Plano, Texas-based computer services giant for $13.9 billion, 12 years after EDS became independent of General Motors Corp.

The years following its spin-off from GM have been challenging ones for EDS. Heightened competition by such companies as IBM, financial losses, and top executive changes marked the company’s experience in the early years of the new century. A new management team installed in 2003 accomplished a financial turnaround by 2006, but growth beyond single digits has remained elusive.

Today the question about EDS’ future prospects was answered. HP will pay $25 per share for EDS, a 32.5% premium over last Friday’s $18.86 share price. The computer services giant, with $22 billion in 2007 revenue, will form the basis of a new business group within the $105 billion HP, to be called EDS, an HP company.

Combined, the two companies have services business revenue of $38 billion, 210,000 employees, and business activities in more than 80 countries.

“It is compelling financially; it is compelling strategically; and it is compelling commercially,” said HP Chairman and Chief Executive Mark Hurd during a conference call today. Added Ronald A, Rittenmeyer, EDS chairman, CEO, and president, “I am absolutely delighted that HP is joining forces with EDS.” Rittenmeyer will report to Hurd after the acquisition’s completion, which is expected in the second half of this year.

For HP, the acquisition fulfills an ambition that stretches back to 2000, when then-CEO Carly Fiorina attempted to acquire the consulting business of PricewaterhouseCoopers for about $18 billion. That attempt, however, failed, and IBM bought PWC two years later for $3.5 billion.

If consummated, HP’s acquisition of EDS will result in HP’s becoming the world’s second largest IT services company after IBM. Big Blue racked up $54 billion in service-related revenue last year.

“The combination of HP and EDS will create a leading force in global IT services,” Hurd said, in a prepared statement. “Together, we will be a stronger business partner, delivering customers the broadest, most competitive portfolio of products and services in the industry.”

But it is in the ability to deliver IT services globally that some analysts still see challenges for the combined HP and EDS.

Philip Fersht, a research director at AMR Research, said in an interview today that both companies still have a way to go in figuring out a global delivery model. “There are significant obstacles,” Fersht said. “Both came of age in pre-global delivery and both are still adjusting. The combined HP/EDS still come up short in consulting and business applications integration compared with Accenture and IBM.”

Still, Fersht said, there are complementary aspects to the merger. EDS, he noted, has a strong business in human resource and call center outsourcing, while HP has strong businesses in finance and accounting. And both companies have sizable footprints in the SAP integration and rollout market.

From a market perspective, though, Fersht said he had not expected consolidation at the top of the IT outsourcing market.

“This came out of left field,” he said, in reference to today’s announcement. “Very few people knew about this until yesterday. We weren’t expecting a consolidation of service companies at the high end.”

In a question-and-answer session during today’s conference call with reporters, Hurd and Rittenmeyer addressed such questions as EDS’ technology partnerships and the new unit’s reach into senior management ranks.

In response to a question about EDS’ Agility Alliance — which includes Cisco, EMC, Microsoft, Oracle, SAP, Sun, and Xerox — both executives said the acquisition would not affect these relationships. “The alliance doesn’t go away,” Rittenmeyer said.

Asked about the combined companies’ prospects of reaching into the so-called “C” suite of senior executives in business, Hurd said that further inroads will be made. “I don’t subscribe that we don’t have C suite access,” he said. “We will get some level of C suite access. We believe we can do many things for a customer now … in a very collaborative way with IT and the C suite.”