Procter & Gamble Co.'s directors are facing a time management challenge: monitoring Chief Executive Officer Robert McDonald's turnaround plan while running their own companies.

Until Angela Braly resigned as WellPoint Inc.'s top executive last week, six of the 10 outside directors on P&G's board were active CEOs, the highest number of any company in the Standard & Poor's 500 Index, according to an analysis by GMI Ratings in New York. Now that Braly is no longer a CEO, P&G ties International Business Machines Corp. with five, GMI found.

The concentration of leaders on P&G's board threatens to turn from benefit to burden as the executives confront financial, operational and macroeconomic difficulties at the companies they run. Braly stepped down from health insurer WellPoint after investors called for her ouster, while James McNerney, another P&G director, is steering Boeing Co. through defense spending cuts and delays to new jets. P&G director Meg Whitman, CEO of Hewlett-Packard Co., had an $8.86 billion record loss last quarter as her company wrote down the value of its enterprise-services unit.