Spearheaded by Starbucks and its chief executive, Howard Schultz, nearly 20 big American corporations will unveil a plan on Monday to find jobs for 100,000 unemployed young people over the next three years.

The effort, to be called the 100,000 Opportunities Initiative, is aimed at the estimated 5.6 million Americans ages 16 to 24 who are neither studying nor working, and will offer full-time positions as well as apprenticeships and internships.

Leaders in government, business and academia are confronting growing income inequality despite steady economic growth and are looking for new entryways into middle-class jobs for American workers who lack a college degree — more than 60 percent of the country’s work force.

At 18.1 percent, the unemployment rate for workers age 16 to 19 remains more than three times as high as the 5.3 percent jobless rate for the entire work force. Unemployment among young people has remained stubbornly high, rising a full percentage point since February, even as other economic yardsticks have improved.