EXCLUSIVE - Southeastern joined by other Dell investors: source

Shoppers walk past a Dell booth at the COMEX information technology and consumers technology exhibition in Singapore August 28, 2008.

NEW YORK (Reuters) - At least three of Dell Inc's (DELL.O) top 20 shareholders support Southeastern Asset Management's decision to vote against the $24.4 billion buyout of the No. 3 PC maker led by CEO Michael Dell, a person close to the matter said.

Among the holders who support Southeastern are Harris Associates LP, Yacktman Asset Management LP and Pzena Investment Management LLC, which between them hold roughly 3.3 percent in Dell, the person said.

Harris and Yacktman were not immediately available for comment. Pzena's chairman, Richard Pzena, said a Dell deal should be in the $20 per share range or the company should explore other options.

(Reporting by Nadia Damouni; editing by Matthew Lewis)