Carol Bartz, the chief executive fired by Yahoo last week, has quit the company's board of directors.
The news comes as The Wall Street Journal reported the company was considering whether to sell itself instead of appointing a new head.
Bartz, who sent an email to employees saying she had been fired over the phone, faced further turmoil last week. A leading investor in the company, Daniel Loeb, launched a campaign to revamp the board and oust Bartz.
"It is time that certain members of this board were held accountable for its past failures and their individual roles," Loeb wrote in a letter to the company.
Yahoo chairman Roy Bostock also supported the move to oust Bartz from the board, alongside two other board members. However Loeb additionally called for Bostock to go, because the departure of Bartz marked the fourth chief executive to exit in four years.
The pressure on Bartz herself had been growing for months, as investors complained over the company's performance. One of the greatest problems has been declining advertising revenue, as the site's popularity falls.
Bartz initially declined to resign from the board, expressing her anger with other members in interviews with the press.
In his letter sent last week, Loeb wrote: "We are adamant that reconstituting the board is crucial to provide any serious CEO candidate or strategic counterparty with a stable and responsive governance structure."
At the weekend, The Wall Street Journal reported that Yahoo has yet to retain an executive search firm, and instead has instructed a board committee to conduct a review into whether Yahoo should be sold or not. Other reports have speculated that co-founder and former CEO Jerry Yang wants to buy the company and is trying to round up investors to back him up, and that AOL and Yahoo are in talks over a possible merger.