Nannette Rodriguez has sold her Hispanic advertising firm, VIVAMEDIA, to Sigler Cos. In addition to being able to use the VIVAMEDIA name, Rodriguez will join the staff of Innova Ideas & Services, Sigler’s marketing and creative services agency, as director of Hispanic marketing. Rodriguez founded VIVAMEDIA in 1996 and says it is the only full-service Hispanic advertising agency in Greater Des Moines. Innova expects with this acquisition that it will expand its reach in the Hispanic market.

Electricite de France SA (EDFI), the largest European power company, said MidAmerican Energy Holdings Co.’s pending $4.7 billion takeover of Constellation Energy Group Inc. undervalues the company and that it has made its own acquisition offer, the Washington Business Journal reported. Its offer, which includes investment partners KKR & Co. LLP and TPG Capital, values Constellation at $35 per share, versus MidAmerican’s planned acquisition for $26.50 per share. EDFI has a 9.5 percent stake in Constellation, making it the largest shareholder, according to Bloomberg data. Constellation CEO Mayo Shattuck said in an investor call on Monday that MidAmerican had the best offer.

Charles Holliday Jr., 60, will step down as CEO of E.I. du Pont de Nemours & Co., parent company of Johnston-based Pioneer Hi-Bred International Inc., at the end of this year. DuPont’s board of directors has elected Ellen Kullman, 52, to replace him. She will become president and director of the company on Oct. 1 and then CEO on Jan. 1. Holliday will remain chairman of the Wilmington, Del.-based company. A 38-year DuPont veteran, he has led the company since 1998. During that time, DuPont completed more than $60 billion in strategic transactions that helped shape the company into a science-based products and services company. In 2007, sales from new products accounted for 36 percent of DuPont’s total sales, up 24 percent from 2001.

Better Homes and Gardens’ branded home products are now available at Wal-Mart stores. The line includes more than 550 products for the bedroom, dining room and living room. The new home collection is the largest-ever extension of the Better Homes and Gardens brand. Based on an agreement between Wal-Mart Stores Inc. and Better Homes and Gardens’ publisher, Des Moines-based Meredith Corp., the line will be expanded with more bedding and bath products, along with outdoor and garden pieces and accents, which are expected to hit stores by fall 2009.

Principal Financial Group Inc. has made the 2008 Working Mother 100 Best Companies list for the seventh year in a row. The company received recognition for the addition of the Principal Child Development Center, which opened this summer, and for its Working Caregiver Leave program, which allows employees to return to their jobs on a part-time schedule with full-time benefits for 12 weeks while caring for a new baby. For the complete list, go to www.workingmother.com.

Well-known architect and author Ed Mazria will present “Now, It’s Personal … A Three-Pronged Solution for Achieving Energy Independence and Solving Climate Change Via the Business Sector, the Largest Energy Consumer in the U.S.” on Thursday from 11:30 a.m. to 1 p.m. at the Greater Des Moines Partnership Building, 700 Locust St., Suite 100, Des Moines. The cost is $20 for Partnership members and $30 for nonmembers. Register at www.desmoinesmetro.com/events.

A former director of the Central Intelligence Agency (CIA) will open the Engineering Policy and Leadership Institute’s first thematic year, “Energy Security and Sustainability.” R. James Woolsey, venture partner with VantagePoint Venture Partners of San Bruno, Calif., and CIA director from 1993 to 1995, will present “Energy and Its Relationship to National Security” on Thursday from 6 to 8 p.m. in the Howe Hall Alliant Energy-Lee Liu Auditorium on Iowa State University’s Ames campus. A roundtable discussion will follow Woolsey’s presentation. This opening event is the first in a monthly series of presentations and moderated roundtable discussions that will cover energy and its relationship to national security, politics, conservation, supply and demand, economic prosperity, alternative energies and agriculture.