UPDATE 2-Cisco, EMC plan partnership, not merger

* To take on IBM, HP in data center

* Both CEOs say they prefer to partner, not merge

* Plan joint venture that also includes VMware, Intel (Adds analysts' comments, details on venture, background)

By Jim Finkle

BOSTON, Nov 3 (Reuters) - Tech heavyweights Cisco Systems Inc (CSCO.O) and EMC Corp (EMC.N) dampened speculation of a merger as they unveiled a partnership to take on rivals Hewlett-Packard Co (HPQ.N) and IBM (IBM.N).

The companies have spent three years developing technology and ironing out the details of a deep partnership through which they will bundle Cisco's networking equipment and server computers with EMC's storage and virtualization technology.

Their goal is to become a top provider of data center products as the industry switches to "cloud" computing services, where data is stored on central servers that can be accessed over the Internet and corporate networks.

Cisco and EMC also announced a joint venture with Intel Corp (INTC.O) called Acadia that will offer to help build and run some data center systems for companies.

As they announced that partnership on Tuesday, top executives from both companies suggested that persistent speculation that Cisco plans to acquire EMC was unfounded.