The move comes on the heels of the departure of the company's chief marketing officer, Cammie Dunaway, who has become the latest in a series of senior executives to leave the company on Friday.
Yahoo! has experienced a troublesome time over the past year, amid fears that Google's more efficient search advertising system has opened up a big gap between the two rivals.
The emergence of new lower-priced forms of display advertising has also damaged Yahoo!'s traditional premium advertising business.
Yahoo!'s shares have been falling, while in June, Terry Semel stepped down as chief executive to be replaced by the firm's founder Jerry Yang.
Semel departed following criticism of Yahoo!'s strategy and falling profits. Earlier this month Yahoo! reported a 5% fall in third-quarter pre-tax profits to $151m (£74.2m).
But Yahoo! is preparing a fightback with the announcement of a new approach at a company-sponsored conference in California.
Yang told the US advertising industry that Yahoo! can differentiate itself by acting as an "open" alternative to its rivals.
Yang said the company was looking to make its big properties into "starting points" that consumers return to repeatedly each day, instead of aiming to keep them on Yahoo as it has done in the past.
"Openness is upon us. There is an opportunity for Yahoo! as a huge publisher to play the open game and do that as a strategy," Yang said in his first public speech since taking the top job four months ago.
The announcement comes at the end of a 100-day strategy review of Yahoo's businesses, in which Yang has vowed there were "no sacred cows".
The shift in strategy will see Yahoo! move away from being a media company that seeks to attract and keep audiences on its own site, towards developing into something more akin to a technology platform that helps users get things done on or off its site.
Yang said: "Yahoo! could be a strong publisher. We may end up continuing to be a strong publisher. But the way we were headed was not creating a publishing platform. We were a bunch of great websites and that was it."