Foreign students in science and technology will be able to extend their stay in the United States, under a new rule to be published by the U.S. Department of Homeland Security this week. The regulation will be welcome relief to some 34,000 students — as well as to colleges and employers — who could have been forced to leave the country this spring because of a legal challenge to a program, Optional Practical Training, that allows them to work in the United States after graduation.

All international students are permitted to work in the United States for 12 months, but a group of American workers challenged an extension of the program for graduates in select science, technology, engineering, and mathematics fields, arguing that the modification, put in place under President George W. Bush, had never gone through the official rule-making process. A federal judge agreed and last summer ordered the Obama administration to put a formal rule in place. She later gave the Homeland Security Department extra time to draft the regulation after the agency was swamped with more than 50,000 public comments.

The new rule, to go into effect in May, will allow students in selected disciplines to work in the United States for up to 36 months. The new rule also says that only students at accredited colleges may qualify for the program, closing an important loophole in the student-visa system. The rule is likely to be applauded by colleges, who see Optional Practical Training as an important recruitment tool overseas.

Lawyers for the American workers, however, continue to contest the legality of the program and have filed an appeal.