The weak national economy and woes in the commercial real estate industry are leading Mid-America Group to drop its affiliation with Grubb & Ellis Co.

Grubb & Ellis/Mid-America Commercial will cease to operate on Oct. 31. Some of the division’s 12 brokers have found other jobs. All will be released at the end of the month. In addition, Grubb & Ellis has agreed to release listings to individual brokers who find jobs with other brokerages, providing their clients agree to the change.

“It’s difficult to have an affiliation with 12 brokers with a national affiliation in one of the worst recessions since the Great Depression,” said Carolyn Helmlinger, Mid-America Group’s president and CEO.

“Grubb & Ellis was just a small part of our business,” said Helmlinger, who also heads the company’s residential division, Coldwell Banker Mid-America Group Realtors. She said Mid-America Group intends to concentrate its resources on the business units that are most profitable, including its residential arm.

The decision, Helmlinger said, followed a “long, laborious process,” which included reaching out to other local commercial real estate firms in town. Mid-America Commercial had considered merging with, acquiring or being acquired by another company, she said. It also looked at other Grubb & Ellis offices outside the state.

Helmlinger declined to disclose if any offers had been made, citing a contractual obligation.

West Des Moines-based Mid-America Group will continue to own, lease and manage all of its company-owned assets, including the 623,000-square-foot Regency West Office Park at the intersection of 50th Street and Westown Parkway, where its headquarters is located.

Its other divisions — Mid-America Development, Mid-America Jet Center and Coldwell Banker Mid-America Group Realtors – will continue to operate.

“Nothing changes,” Helmlinger said.

“In essence, we are just taking back our stuff,” she said, adding that the company will continue to market and lease its more than 1 million square feet of Class A office space and more than 1 million square feet of industrial space. “All properties owned by Mid-America Group,” including its development ground and various other investments, “will be managed in-house,” she said.

The Mid-America Group was founded in 1961 by the late Marvin Pomerantz. Helmlinger became president of the company following the resignation of Teresa Wahlert in October 2008.

Grubb & Ellis Co., one of the largest commercial real estate services and investment companies in the world, lists on its Web site more than 130 company-owned and affiliate offices.

Mid-America Commercial will continue as a shell company, Helmlinger said. “The name will be held, but it won’t be on the street.”

Larry Cedarstrom, president of Grubb & Ellis/Mid-America Commercial, and Debra Kastantin, the company’s research director, will lose their jobs as a result of the change.

“It’s strictly an economic decision made to preserve resources for other entities we have in the Mid-America Group,” Helmlinger said. “We will do whatever we can to help assist in the transition.”