By Stephanie Simon

(Reuters) - U.S. college admissions officers on Wednesday welcomed new rules aimed at deterring cheating on entrance exams, but continued to raise concerns about fraud, especially among foreign applicants.

The new regulations require students taking the SAT and ACT, the two most widely used college entrance exams in the United States, to provide a photo of themselves when they register.

Test proctors will be asked to check those photos against identification cards students present when they check in for the exams - and against the students themselves.

The change is designed to deter schemes like that uncovered last year in Long Island, New York, where prosecutors allege dozens of teens paid other students up to $3,600 to take the high-stakes exams for them.

As a further security measure, the SAT and ACT will make students' registration photos and test results available to their high schools, so administrators who spot a suspiciously high score can double-check the test taker's identity.

The ACT covers math, science, reading comprehension and grammar, with an optional writing section. The SAT covers reading, writing and math.

David Hawkins, director of public policy for the National Association for College Admission Counseling, called the new rules a positive step to crack down on test-taking-for-hire.

But the measures do nothing to address a more pressing concern among college admissions officers: The fear that they are being flooded with fraudulent applications from abroad.

The number of foreign students enrolling in colleges has skyrocketed in recent years, to nearly 725,000 in 2010-11, according to the Institute of International Education. China and India send by far the most students to American campuses, though numbers are also soaring in Saudi Arabia, Vietnam and Iran.

Admissions officers say they have seen growing indications of fraud on application forms, including fabricated transcripts, forged letters of recommendation and personal essays so polished they seem unlikely to have been written by the student.

CHEATING IN CHINA

Zinch China, a consulting firm that advises U.S. colleges about foreign markets, asserted in a 2010 report that "cheating is pervasive in China," with as many as half of all applicants submitting forged transcripts and up to 90 percent dummying up phony recommendations.

For a more objective assessment of an applicant's strengths, admissions officers often rely on the TOEFL standardized test, which measures fluency in English, as well as the SAT and ACT, which are administered in dozens of nations worldwide, from Afghanistan to Bhutan to Kyrgyzstan to Yemen.

But stellar scores are not always what they seem, Hawkins said. "Often a student seems very qualified on paper, only to find out when they arrive on campus that they don't speak English nearly as well as you would have expected," he said.

The Educational Testing Service, which administers the TOEFL, does not require students to present a photo ID and has no plans to do so, said Ray Nicosia, director of the Office of Testing Integrity.

Instead, TOEFL proctors take a photo of every student as he or she sits for the exam. If a student takes the test more than once and shows remarkable improvement, the pictures from each sitting are compared to rule out fraud.

But there's no way to catch a student who pays someone to take the test for him the first time he registers.

"It's an issue that many of us are dealing with and I don't think we've come up with the best solution," said Brian Henley, director of admissions at the University of Oregon, where foreign students make up 8 percent of the student body.

Henley said he has noticed a big jump in TOEFL scores among this year's applicants, which "may be due to more effective language training in Chin" -- or to "increased fraud," he said.

"It's really hard to know," Henley said. He urged test administrators to improve security but acknowledged it may be impractical to require photo IDs or photo registrations in many impoverished or war-torn countries.

TOEFL CHEATS SAID TO BE FEW

The Educational Testing Service will not release information about how many students take the TOEFL or how many exams are thrown out due to suspicion of cheating.

"It is a very, very small percentage of the population who try to gain an unfair advantage over honest test takers," said ETS spokesman Thomas Ewing. "Our processes and procedures are very good at catching such people and we have no qualms about cancelling scores and notifying universities."

The ETS also administers the SAT, and will put the new photo ID security measures in place at SAT test centers abroad as well as in the United States, Ewing said.

ACT, Inc., which administers the ACT, has not determined how it will incorporate the new security measures abroad, spokesman Scott Gomer said. "We don't have a strict timeline," he said.

It is not clear how common it is for American students to hire impostors to take tests. Out of more than 2 million students who signed up for the SAT last year, just 170 were turned away because of problems with identification, said Nicosia said.

Scores on roughly 3,500 additional tests were thrown out because the students violated SAT rules during the exam - for instance by using a cell phone - or because a post-test review suggested cheating, Nicosia said.