Constructing a company by way of mergers and acquisitions is hard work. Taking one apart can be even more daunting. "I think the biggest challenge for us in finance and treasury was the sheer magnitude of what needed to be done in a short period of time," says David Wyshner, executive vice president, CFO and treasurer of what is now called Avis Budget Group.

Back in 1998, Cendant was involved in one of the nation's largest corporate accounting fraud cases, when its top management inflated revenues of the business and consumer services giant by $500 million. The company recovered, but its shareholders ultimately pushed management to agree to break up the conglomerate into four more narrowly focused enterprises: Realogy, Wyndham Worldwide, Travelport and Avis Budget Group.

That separation, announced by Cendant on Oct. 24, 2005, was implemented less than a year later in July 2006. It required a Herculean restructuring of the company's financing, so that each of the four new independent companies–all major multibillion-dollar players in their respective industries–would have adequate standalone financing. That task fell largely to Wyshner, treasurer since January 2004.