According to reports in the US, within days of Yahoo's rejection of Microsoft's takeover approaches, three executive vice-presidents, two senior vice-presidents and several senior employees have announced their intention to leave the company.
Last week, Yahoo sought to appease investors concerned over its future by announcing a deal with Google under which Google ads will appear on Yahoo search engine results.
Butterfield's resignation comes as three more senior executives resigned from Yahoo - Qi Lu, executive vice-president of engineering for search and advertising technology, Brad Garlinghouse, senior vice-president for communications and communities, and Vish Makhijani, senior vice-president of Yahoo's search group.
The departures put more pressure on Yahoo's embattled leadership, chief executive Jerry Yang and president Susan Decker.
In recent weeks, the company has come in for fierce criticism from billionaire investor Carl Icahn, who has sought to replace Yahoo's management board and replace it with executives more open to talks with Microsoft.
United Kingdom
Yahoo executive exodus gathers pace
LONDON - Yahoo has been hit by the departure of one of its most senior executives, Flickr founder Steve Butterfield, as the exit of senior management from the company continues.