CBS Corp. (CBS) said Joseph Ianiello will become chief financial officer next month as Fred Reynolds retires in August after a 38-year career in finance and business strategy.

Ianiello, 41, was appointed deputy CFO last November, and he was widely viewed as a likely successor to Reynolds, 58, whose employment contract was up for renewal in August. Reynolds ran CBS' station group before the company was separated from Viacom at the end of 2005, and he almost left to join private equity firm Evercore Partners at the time of the split, but CBS Chief Executive Les Moonves convinced him to stay on as his CFO.

Moonves said in an interview that Reynolds, who sits on the board of directors of Kraft Foods Inc. (KFT), recently informed him he was considering moving on with the end of his contract.

"There was no pushing him out the door here," said Moonves. "This is how it's supposed to be when a guy wants to move on, and I'd be more worried about it if we didn't have someone like Joe ready to step into the job." Moonves said.

Reynolds was a lead negotiator for CBS in its split with Viacom and "has guided our finance division through virtually every major transformative event of the last 15 years." Those also include the company's acquisition by Westinghouse in 1995, its Infinity acquisition in 1996 and the Viacom-CBS merger in 2000.

Reynolds said Ianiello "has been my financial partner on virtually every crucial transaction of this company over the past several years." He said a large part of his decision to retire now was based on knowing he could pass the reins to Ianiello.

Ianiello will step into the job at a difficult time for CBS as the company faces unprecedented financial pressures and the traditional media industry suffers decline from the rise of digital media. Shares of CBS are down 15% so far this year after losing nearly two-thirds of their value last year amid the global financial crisis and economic slowdown.

Standard & Poor's recently downgraded the company's credit rating to one notch above junk, even after the company successfully raised about $1 billion in the credit markets to shift a heavy load of debt maturities it faced over the next several years into longer-dated bonds.

"We're very focused on maintaining an investment grade credit rating," said Ianiello. "Trends are improving and there are signs that ad markets have hit bottom, so my hope is that we can climb back up the ladder of investment grade over time."

For his part, Moonves said he's confident the company will maintain its investment grade rating. He said no upfront deals with advertisers for the new TV season have been reached yet and he expects volume to be down for the season while prices will be higher.

"The normal dance where the agencies try to hold back for lower prices is going on now," said Moonves. "Maybe it's harder than usual, but the networks aren't caving and they feel very sanguine about it. We like our position."

Reynolds will step down as CFO July 20 but remain executive vice president while working with Moonves and other executives on the transition of his duties before his Aug. 15 retirement.

CBS's shares were recently down 6.3% at $6.88 amid a broader market downturn.

-By Nat Worden, Dow Jones Newswires; (212) 416-2472; nat.worden@dowjones.com

(Kerry E. Grace contributed to this story.)