Lisa Bannon and Rebecca Smith:

American universities are searching for ways to generate more revenue. As a result, hundreds of schools—including Vanderbilt University, the University of California, Berkeley, and the University of North Carolina at Chapel Hill—are teaming up with for-profit companies such as 2U to provide online programs.

As part of the arrangement, one that is reshaping higher education, universities sometimes hand over to companies a great deal of control of student recruitment and instructional design, especially for nondegree programs. For their work, the companies receive hefty shares of tuition dollars.

Much of this isn’t clear to prospective and current students. Universities often cooperate with companies in ways that can blur the lines for students between schools and recruiters.

2U, based in Lanham, Md., has emerged as a leader in the booming field, employing aggressive recruiting practices and in some cases playing down its role, according to interviews with current and former 2U employees and students.

Christopher “Chip” Paucek, 2U’s chief executive and a co-founder, said the company is providing valuable services to universities that many can’t do themselves. “For the last 14 years, 2U has worked to expand access to high-quality online education for learners around the world, enabling hundreds of thousands of students to transform their lives,” Mr. Paucek said in a written statement.

Christina Denkinger wanted something new after 14 years as an elementary-school teacher in Portland, Ore. After shopping around for a course in data analytics last fall, she requested information through a University of Oregon website portal for an online training program, called a boot camp, offered by the university’s continuing-education division.