Yahoo Search engine (The Second Giant in Search Engines) announced on last Monday that CEO Terry Semel has resigned from his 6-year service. The company co-founder Jerry Yang is takeing over Terry’s duties and Semel remains as chairman for non-executive role.

Also to naming Yang CEO, Yahoo appointed Susan Decker as its president, who had been given to oversee Yahoo’s advertising operations recently.

This announcement comes right a week after Semel faced off with Yahoo shareholders disenchanted with Yahoo’s lackluster performance within the past year and a half. Semel will not receive a severance package, as he has almost made $450 million in gains by doing some of the stock options he received during his tenure, as Yahoo says.

By that, Yahoo shares goes up 81 cents Monday with a closing at $28.12, after that jumped to $1.33, or 4.7% in extended trading.