Martha Willits, president and CEO of the Greater Des Moines Partnership, will retire at the end of the year after spending seven years with the organization. Partnership board chairman Larry Zimpleman of Principal Financial Group Inc. said a search committee will work with the Partnership’s members and affiliate members, as well as local public-sector, nonprofit and education leaders, to identify candidates to fill the Partnership’s chief executive position. “I look forward to continuing to assist this forward growth in 2012 by connecting in new ways to the Partnership’s work,” Willits, 64, said in a release. Those interested in the position should click here to find more information on the application process.