President Bush chose federal appeals court judge John G. Roberts Jr. today as his first nominee for the Supreme Court, selecting a rock-solid conservative who has won broad support from both parties but still faces what could be a contentious battle over the direction of the nation's highest court.

Bush offered the position to Roberts in a telephone call at 12:35 p.m. as he was hosting a luncheon for the prime minister of Australia, John Howard. He was to announce it later with a flourish in a nationally broadcast speech to the nation.

His selection was somewhat of a surprise since there had been some expectations that he would replace retiring Justice Sandra Day O'Connor with a woman or minority.

Roberts has been on the U.S. Court of Appeals for the District of Columbia Circuit since June 2003 after being picked for that seat by Bush.

Advocacy groups on the right say that Roberts, a 50-year-old native of Buffalo, N.Y., who attended Harvard Law School, is a bright judge with strong conservative credentials he burnished in the administrations of former Presidents Bush and Reagan. While he has been a federal judge for just a little more than two years, legal experts say that whatever experience he lacks on the bench is offset by his many years arguing cases before the Supreme Court.

Liberal groups, however, say Roberts has taken positions in cases involving free speech and religious liberty that endanger those rights. Abortion rights groups allege that Roberts, while deputy solicitor general during former President Bush's administration, is hostile to women's reproductive freedom and cite a brief he co-wrote in 1990 that suggested the Supreme Court overturn Roe v. Wade, the landmark 1973 high court decision that legalized abortion.

"The court's conclusion in Roe that there is a fundamental right to an abortion ... finds no support in the text, structure or history of the Constitution," the brief said.

In his defense, Roberts told senators during his 2003 confirmation hearing that he would be guided by legal precedent. "Roe v. Wade is the settled law of the land. ... There is nothing in my personal views that would prevent me from fully and faithfully applying that precedent."