Donor Withholds $60-Million of Gift

The Internet entrepreneur Jim Clark is withholding the balance of a $150-million pledge to create a biomedical center at Stanford University, citing his objection to the Bush administration’s policy on embryonic stem-cell research.

Mr. Clark, founder of Netscape, said he would not donate the remaining $60-million of his 1999 pledge unless the federal government altered the policy announced last month by President Bush. That policy restricts federal support of such research to existing lines of embryonic stem cells. Researchers worry that those lines will be insufficient for their studies.

Stanford, which has begun construction on the biomedical facility, says it will raise money from others to complete the project.