Yum CEO faces first big test as Taco Bell outbreak clouds earnings

The results provide investors an early assessment of Turner, a company insider appointed CEO in October last year, as he confronts the company's biggest crisis soon after announcing the $2.7 billion Pizza Hut sale.

"Every new CEO gets a defining moment; Chris Turner is finding his sooner than most," said Michael Ashley Schulman, partner at Cerity Partners.

Investors are expected to give Turner, who has previously worked at PepsiCo and consulting firm McKinsey & Co, some room as he seeks to reinvigorate growth.

Yum is also battling an industrywide slowdown, as elevated inflation encourages consumers to spend more cautiously and the growing use of GLP-1 weight-loss drugs spurs healthier eating.

The company, which typically refrains from providing forecasts beyond current-quarter sales and earnings trends at its chains on investor calls, is expected to post second-quarter comparable sales growth of about 3% and a roughly 10% rise in adjusted profit for the three months ended June 30, according to LSEG estimates.