Steven M. Blondy, the finance chief of Dex One, plans to resign from the Cary yellow pages publisher.

Blondy, 51, will step down by July 31, and the company has started a search for  a new chief financial officer, Dex One announced this morning.

He will receive a lump-sum separation fee of $2.6 million, plus other benefit payments, Dex One reported in an filing with the Securities and Exchange Commission.

Blondy has been CFO of the company previously known as R.H. Donnelley since March 2002.

Dex One, the Cary-based yellow pages publisher, reported weaker ad sales during the second quarter and warned that the shaky economy will continue to hurt results.

The company changed its name to Dex One from R.H. Donnelley when it emerged from bankruptcy protection earlier this year. The company filed for bankruptcy to clear some of its massive debt as ad sales slumped.

During the second quarter, ad sales fell 13.4 percent. Dex One also noted that it expects ad sales to decline up to 15.5 percent for the full year, more than it previously projected. Still, those figures are an improvement from the steep declines seen during the worst of the recession.