EMC, the maker of storage computers, facing the retirement of chief executive Joseph Tucci and activist pressure, is exploring strategic options that could include a full or partial sale, or a spinoff of VMware Inc.

Insight Venture Partners topped a $25.50-a-share bid that Quest Software received from an unidentified suitor, intensifying a takeover battle for the software maker, according to a person familiar with matter.

Quest Software, a maker of software to help companies manage cloud computer systems, rose above a new $25.50-a-share cash buyout offer from a strategic bidder that topped a previous agreement with Insight Venture Partners.