Lansing (MI) - Several Yahoo shareholders have jointly filed a lawsuit against the online giant after it failed to agree to a nearly $45 billion acquisition offer from Microsoft.

Last week, Microsoft announced it was looking to buy Yahoo for $44.6 billion but Yahoo ultimately decline, saying it was worth more than the presented offer. Michigan’s Wayne County Employees’ Retirement System, which owns over 13,000 shares of Yahoo, argue that Yahoo failed to enter substantial negotiations with Microsoft.

As a result, they filed a lawsuit saying that Yahoo executives "are entrenching themselves in office and protecting and advancing their own interests at the expenses of Yahoo and its stockholders while Yahoo’s stock price languishes."

"The board of directors is continually evaluating all of its strategic options. Our board believes the Microsoft proposal substantially undervalues Yahoo," Yahoo spokesperson Diana Wong told Bloomberg News.