Harvard University has sold millions of dollars in shares in Israeli companies, a move that it insists is purely financial but which has already been claimed by a pro-Palestinian group as a victory in its boycott and divestment campaign against Israel.

Groups sympathetic to the Palestinians have been pressing universities in the US, the UK and elsewhere to end investment in Israel and to boycott Israeli academics.

Harvard's decision to sell its shares emerged on Friday when it notified the US securities and exchange commission. The sale, in the second quarter of this year, included $30.5 million (£19.4 million) worth of shares in Teva pharmaceuticals, $3.6 million in Check Point software technologies and $1.1 million in Cellcom Israel.

A Harvard spokesman, John Longbrake, said today the changes in holdings were routine and not a change in policy. "The university has not divested from Israel," he stated.

Harvard said the change had taken place because Israel had been part of its emerging markets portfolio but the country's status had been upgraded to developed market.

Longbrake added that the university retained shares in Israel: "We have holdings in developed markets, including Israel, through outside managers in commingled accounts and indexes, which are not reported in the filing in question."

Harvard has divested in the past for political reasons but admitted it publicly at the time. In 2005 it divested funds from PetroChina, an oil company, because of China's involvement with Sudan, which was engaged in genocide in Darfur.

Students and staff at the university pushed for divestment from Israel in 2002 but their campaign was swamped by an one opposed to the action. Pro-Palestinian groups claimed Harvard was responding now to the bad publicity that has plagued Israel since its attacks on Gaza and on the international flotilla bringing aid to the Palestinians in May.

Speaking before Harvard issued its statement, Hind Awwad, coordinator of the Palestinian Boycotts, Divestment and Sanctions National Committee, was quoted by the website Media Line saying: "We welcome Harvard's decision and encourage all academic institutions in the US and elsewhere to follow its lead, to invest in socially responsible investments and divest from Israeli war crimes."

One of divestment's leading opponents at Harvard, Professor Alan Dershowitz, said he had checked with those involved in the decision to sell the shares and was satifisfied it was purely technical. "There will be some irresponsible anti-Israel extremists who will try to portray this economic decision as an attack against Israel," Dershowitz said. "Shame on them. They will continue to lose their credibility among all reasonable and objective people if they try to take political advantage of this purely technical decision."

He added: "The end result may well be that Harvard will have greater rather than lesser holdings of Israeli stocks. No one should misinterpret this purely economic decision as support for any form of divestment against Israel. Indeed, Harvard has publicly committed itself not to divest from Israel and not to participate in any campaign of boycotting the Jewish nation."

The idea of boycotts and divestment against Israel was inspired by a similar strategy that some credit with bringing an end to apartheid in South Africa. US churches, students, academics, and others took a lead in that campaign.

Although students and academics on campuses across the US have intermittently organised campaigns against Israel, so far they have recorded no successes.

Students at Hampshire College in Massachusetts conducted an intensive campaign for divestment but reports last year that the college had buckled and was the first in the US to divest proved erroneous. The college said it retained shares in at least three Israeli companies.