Traders are pushing derivatives linked to Procter & Gamble Co. debt to the riskiest level relative to Colgate-Palmolive Co. and lower-rated Unilever since 2009 on concern that investor Bill Ackman will pressure the company to reward shareholders at lenders' expense.

The cost to protect bonds of the world's largest consumer-goods maker from default has increased 10.2 basis points to 0.62 percentage point yesterday in New York since July 11, after Ackman bought a $1.8 billion stake in P&G. While the stock has since gained 5.6 percent as bullish options wagers surge, bonds of the maker of Tide, Pampers and Crest are underperforming as profit margins narrow and sales growth decelerates to the slowest since 2009.

Ackman may persuade management to reinstate its share repurchase program with debt-sale proceeds, according to bond research firm Gimme Credit LLC, after its stock fell almost 10 percent from the 2012 high. Cincinnati-based P&G's swaps were less expensive than those of Colgate and Unilever a year ago.