Britain withdrew its two defense attaches from the British Embassy in Pretoria today, saying it had decided to join its partners in the European Community in adopting a series of punitive measures against South Africa's apartheid rule.

A statement issued by the Foreign Office called the measures "a legitimate and necessary political signal to the South African government, but one which avoids further destablization of the South African economy and harming those in South Africa whom we are seeking to help."

It said that while Britain still opposes mandatory economic sanctions, it felt that the community measures would help "secure the urgent and fundamental changes for which we have repeatedly called."

Britain abstained two weeks ago when the other nine community members, plus incoming members Spain and Portugal, agreed to implement measures including arms and oil embargoes, bans on military and nuclear cooperation and curbs on cultural and sports links with South Africa.

Officials said the British decision followed an internal review finding that, with the exception of the curb on military ties, the measures would have little effect on current policy.

At the same time, one official noted, "the British government was very keen not to find itself completely isolated on this issue."

South African Foreign Minister Roelof F. Botha quickly condemned the move as "shortsighted and uncalled for" and said that it would "not contribute to the process of reform" there.

But the two-week British delay was likely to lessen the overall political impact of what already had been described as a program with limited punitive clout. Most of the measures adopted at the Sept. 10 EC meeting in Luxembourg already had been imposed by the individual countries -- including Britain -- or through the United Nations. The community was unable to agree on stronger steps, such as suspension of new investments in South Africa.

Britain argued at the Luxembourg meeting that its ties with South Africa were much more substantive than those of the others, and said it would abstain from the accord until it had conducted a review of how each of the measures would affect those ties.