By Svea Herbst-Bayliss

BOSTON (Reuters) - Harvard and the Massachusetts Institute of Technology, both academic heavyweights and often neighborly rivals, are joining hands in a new partnership to offer courses online and for free.

The two schools, located near each other in Cambridge, Massachusetts, are teaming up on an initiative called edX only five months after MIT rolled out MITx, its online learning system which allows students to earn certificates for completing course work from a distance.

Harvard and MIT each committed $30 million to the project, which will be overseen by a not-for-profit group based in Cambridge. Anant Agarwal, who led the development of MITx and directed MIT's Computer Science and Artificial Intelligence Laboratory, will be edX's first president.

The group plans to offer its first courses in the fall and eventually expects other universities may join.

With a wink to the schools' long-running rivalries in racing to academic breakthroughs and wooing professors and students, MIT President Susan Hockfield said they also work together. "One of the best-kept secrets is the profound richness of collaboration between Harvard and MIT," she said at a news conference, standing next to Harvard President Drew Faust.

Online learning has become a hot topic in education with many schools, including MIT, offering hundreds of courses online where students work through the material at their own pace but are not tested. Now the trend is to offer classes online where students can earn certificates if they show they can master the subject.

MIT said 120,000 people signed up for the first such course - Introduction to Circuits and Electronics - that MITx rolled out earlier this year. Halfway through the course, some 20,000 were still actively keeping up with it.

The new program is expected to make Harvard and MIT's course work available around the world to students who cannot sit in classrooms on campus, and officials also expect it to aid researchers in figuring out new ways for people to learn.

"EdX gives Harvard and MIT an unprecedented opportunity to dramatically extend our collective reach by conducting groundbreaking research into effective education and by extending online access to quality higher education," Harvard's Faust said.

The students who sign up, free of charge, will be able to watch video lesson segments, take embedded quizzes and participate in online laboratories.

And they will be able to earn certificates for completing the work. But university officials have long underscored that these online learning platforms are not a less strenuous path to a top-tier diploma. Indeed diplomas can still be earned only by being admitted by the schools and attending classes in person.

Harvard and MIT are extremely selective with Harvard accepting only 5.9 percent of the applicants for an undergraduate degree this year. MIT accepted 8.9 percent.

(Reporting By Svea Herbst-Bayliss; Editing by Jackie Frank)