Following a Dell (DELL.DL) proxy statement filed earlier this month in which the PC giant provided a pessimistic analysis of its business, major institutional investor Southeastern Asset Management has issued an open letter questioning the company's conclusions.

Southeastern Asset Management owns an 8.4% stake in Dell, and says in a press release today that it believes the analysis yielded an "inadequate outcome."

Southeastern has been vocally against the $13.65-per-share buyout offer proposed by Michael Dell and Silver Lake earlier this year. The firm notes that Dell has repurchased shares at an average price of $15.25 over the past year, yet now recommends that investors sell the company for a lower price.

Southeastern maintains that Dell's pessimistic analysis places too much emphasis on the PC market, while ignoring its potential in its enterprise storage and services segment. Before the buyout offer was on the table, Dell used to emphasize the future potential of this segment.

The investment management firm believes the analysis is misleading and it considers the two preliminary alternative acquisition proposals superior.