ZURICH, Aug 4 (Reuters) - Adecco has not delivered the growth expected of it, new CEO Denis Machuel told analysts on Thursday, adding he will be brutally honest as he examines the staffing company's under-performance.

The former CEO of food services company Sodexo said he will focus on delivering returns from investments and growing market share at Adecco which competes with Randstad and ManpowerGroup.

"We clearly have areas of under-performance," said Machuel, who took charge in July. "The U.S. for Adecco is one of them, we will strongly focus on that.

"I will call a spade a spade in those areas in order people understand what is really expected of them and turn these situations around," he said. (Reporting by John Revill; editing by Jason Neely)