While regulatory approval has been known to halt a merger in its tracks, a $35 billion pending acquisition that could have resulted in the largest advertising agency on the planet has been scrapped for decidedly more personal reasons.

U.S.-based advertising giant Omnicom and its French counterpart Publicis have tossed out a deal announced last July, primarily due to internal cultural clashes and power struggles within the forthcoming entity’s executive suites, Reuters reports.

“Omnicom wanted their people to fill the CEO, CFO and general counsel jobs,” Publicis chief Maurice Levy told the outlet. “I thought that went too far. I was not ready to cede on this point.”

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“There are strong corporate cultures in both companies that delayed us reaching an agreement,” Omnicom CEO John Wren explained -- and these delays had resulted in astronomic losses of work, namely more than $1.5 billion in the past month alone.

Approximately 65 percent of mergers falter -- primarily due to lack of corporate blending, says Alan Smith, CEO of the M&A consulting firm Bay Pacific Group.

"The danger time in a corporate culture clash is in the very beginning when employees on both sides feel threatened by the combination," he advises. "By acknowledging its presence early on and educating employees as to its dynamics, people will be better prepared to appreciate differences that may help build a stronger organization in the long run."

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Though the deal would have called for 50-50 ownership and had been initiated to cope with an evolving ad industry increasingly dominated by tech giants like Google and Facebook, both sides ultimately fell prey to a corporate soap opera of sorts.

There were also complications over legal and tax issues -- and also of note was that China’s antitrust regulator, Mofcom, had not granted the deal regulatory approval, notes The New York Times.

As they go their separate ways, both Omnicom and Publicis face no termination fees, but will split the legal bills resulting from the failed transaction.

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