The Navy has released a much-anticipated solicitation for a program worth as much as $4.5 billion over five years to manage a next-generation version of its intranet.

Contractors have already put together teams to bid on the program, which would replace an existing contract that provides a Navy and Marine Corps intranet serving more than 800,000 people in more than 2,500 locations.

The initial program was awarded in 2000 to Electronic Data Systems — better known as EDS and later purchased by Hewlett-Packard. Though the contract was set to end in 2010, HP received a follow-on contract that could end as late as April 2014.

The solicitation released earlier this month for the Next Generation Enterprise Network, or NGEN, calls for proposals by July 18 and says the Navy plans to announce an award in February 2013.

A winning contractor or contractors, the solicitation says, should be able to operate the network, ensure its security and make a successful transition from the existing network, among other capabilities.

The initial, 10-year contract with EDS/HP totaled more than $10 billion in spending, said Capt. Shawn P. Hendricks of the Naval Enterprise Networks program office in a roundtable with reporters last week.

There “has been massive interest” from users of Herndon-based Deltek, which analyzes the government contracting market, said Lora Settle, a Deltek research analyst specializing in NGEN. Since 2007, “we’ve had a large majority of our members express some interest in this at some point.”

While Settle said she only expects one awardee, contractors will be able to team and to subcontract.

HP, the incumbent, said it will “thoroughly review” the solicitation, adding in a statement that its experience makes it “best-suited.”

Falls Church-based Computer Sciences Corp. is teaming with Harris, which is a subcontractor to HP on the existing effort, as well as Verizon and General Dynamics.

Ken Deutsch, vice president and lead executive for the NGEN program at CSC, said he doesn’t know of other teams planning to compete.

“Within the two teams we have here, I anticipate it will be fiercely fought,” he said.