Professor Caroline Gipps, deputy vice-chancellor at Kingston university, told the HMC that students can be coached for the tests, confusingly known as SATs, despite claims that they test for potential alone.
Taken by all American university candidates, the tests have powerful backers, including Peter Lampl, the millionaire philanthropist who spoke at the conference. They believe the tests allow students from uneducated backgrounds to demonstrate their ability more fairly than at A-level.
They are among a range of options being looked at by the Government's committee on improving access to higher education, chaired by Professor Steven Schwartz, vice-chancellor of Brunel university.
British universities are under pressure from ministers to admit more students from non-traditional backgrounds. But according to Professor Gipps, introducing the tests will only add to the bureaucracy, with no obvious benefits.
"If you want to turn marginal kids off learning, this is the way," she said. "Assess them like mad at 16,17 and 18. I do not think it would improve social class difference in terms of access to university."
She pointed to a National Foundation for Educational Research study which has already questioned the idea that the tests are class neutral. "The SAT is a matter of what people have learnt," she said. "Although it is described as a test of potential, it is much more a test of achievement."
Professor Gipps also called for the return of norm referencing in A-level, a move which would end grade-inflation by awarding a fixed percentage of A-E grades every year, whatever the standard of the papers overall.
This system was used until the late 1980s. It would, she said, help universities and employers distinguish the most able, although more sophisticated measures of students' worth would also be needed.
Earlier, Lord Butler of Brockwell, master of University College Oxford, attacked Labour's higher education policies, describing the 50 per cent participation target as "capricious". He said that universities should be free to charge as much as they want on condition that they also provide bursaries for students from deprived or under-represented backgrounds. This could leave students with debts of pound;10,000 a year rather than the annual pound;3,000 under the Government's current proposals which, he says, are inadequate.