In an effort to curb escalating book prices amid sky-high college costs, bookstores at more than a dozen campuses across the state and hundreds more around the country will begin renting textbooks at about half the cost of buying them.

At other schools, professors looking to save students even more money are solely assigning reading materials accessible over the Internet — for free.

The move toward more affordable options comes as federal legislation to control runaway textbook costs kicked in this month. Textbook prices have risen 14 percent in the past year, according to a major book retailer, growing at four times the rate of inflation for many years.

A typical undergraduate today spends $900 to $1,200 a year on textbooks, compared with $400 to $600 a decade ago, said Joseph Mercurio, executive vice president of Boston University.

“Professors would have no idea what the price was until students came in and complained,’’ said D. Steven White, professor of marketing and international business at the University of Massachusetts Dartmouth.

The new law, passed by Congress as part of the Higher Education Opportunity Act in 2008, will make professors more aware of the cost of textbooks by mandating that publishers disclose the prices during the marketing process.

Publishers must now also offer students the option of buying books without compact discs, study guides, and other bells and whistles that used to accompany some texts automatically but hiked up the prices. During course registration, colleges must make available the list of textbooks assigned for each class so cash-strapped students have time to shop around for the best deals.

As schools and publishers bring more transparency to textbook costs, some professors and college business managers predict that will drive more students to alternatives like renting. For less than half the cost of buying that pricey Economy 101 tome, students at a wide range of colleges including Clark, Merrimack, and UMass Dartmouth will be able to borrow it, even highlight and mark up the pages, as long as the book is returned in good condition at the end of the term.

Barnes & Noble will roll out the rental program at BU and more than 300 colleges across the country this fall. Follett, the nation’s largest campus bookstore operator, will introduce the concept at more than 800 schools nationally, including Curry College, Wentworth Institute of Technology, Lasell, and Suffolk. Cengage Learning in Stamford, Conn., the first textbook publisher to rent books directly to students last year, has more than doubled the number of titles for rent to more than 3,000.

BU’s bookstore will start renting 900 of its most popular titles, including the ones used in introductory courses, which are often the most expensive, Mercurio said.

“Students were asking for this,’’ he said. “Now, we’ll see. This is an experiment of sorts. The books have to be returned in good condition, and we have to be able to rerent them a second and a third time.’’

Students who end up wanting to keep their books at the end of the term can opt to buy instead of returning them.

BU sophomore Jasmine Little spent $250 on a Spanish textbook last fall that she would have preferred to rent if she could have. “It was a shock to me, especially coming from a public school where I didn’t have to pay anything for textbooks,’’ Little said.

The cost is especially infuriating, students said, when professors don’t finally use all the books they ask their students to buy. Some savvy students, though, have found ways to cope without breaking their budgets.

Giuseppe Caruso, a BU senior, has not stepped foot in the campus bookstore in more than two years. He scours online sites like Amazon.com and Half.com for discounted used books, saving himself $500 last semester.

Sophie Monroe, a senior at Boston College, e-mails her professors as soon as she is considering a course and asks for their reading lists. She tries to buy as many books as she can from friends who have taken the class.

“Textbook cost is one of the biggest burdens for me,’’ Monroe said. Her method allowed her to spend $300 last fall, instead of $900, she said.

Other students use textbooks on reserve at the library or simply share with friends. But professors worry that the inconvenience can mean weeks of unread chapters or little understanding of the material. And 15 percent of college students never bother to buy books, according to Follett researchers.

At UMass Dartmouth, White has stopped using textbooks in his business classes. Instead, he finds materials students can download for free from Flat World Knowledge, a three-year-old, open-source textbook publisher based in New York. When the company released its first books online in spring 2009, 450 professors used them; this fall, 1,300 will, said president and cofounder Eric Frank.

Students in White’s class who prefer a hard copy of the business and economics textbooks can print the materials for $25 or pay $30 for a black-and-white bound version and $60 for a full-color text, which is still half the cost of a standard economics textbook, White said.

Students can also pay extra for digital flashcards, audio study guides, and practice tests.

John Gallaugher, BC information systems professor, wrote a textbook for Flatworld last fall that more than 100 business professors have adopted, including colleagues at Carnegie Mellon, the University of Southern California, and the University of Michigan. Last week, he released an updated version with new chapters using more current examples.

The company currently publishes 20 titles online. By next spring, it plans to offer 45 and will expand beyond its business and economics niche to psychology, sociology, and algebra.

“This is the future,’’ Gallaugher said. “For less than $30, the cost of dinner and dessert at Applebee’s, you can get in print what you used to have to pay $180 for.’’

Tracy Jan can be reached at tjan@globe.com.