Factbox - U.S. top court rulings on campus racial affirmative action

(Reuters) - The U.S. Supreme Court sidestepped a major ruling on Monday in a closely watched case on the University of Texas's affirmative action student admissions policy, sending the case back to a lower court to consider.

It marked the top U.S. court's latest decision relating to university policies that consider an applicants' race in the admissions process to ensure campus diversity.

Here is a look at three important university affirmative action cases over the past 35 years.

* Regents of the University of California v. Bakke, 1978. By a 5-4 vote, the court ruled universities may consider an applicant's race as one of many factors in admissions but they may not impose quotas or set aside a set number of places for minorities. Justice Lewis Powell highlighted the value of diversity in education as he provided the key fifth vote for both parts of the ruling.

* Grutter v. Bollinger, Gratz v. Bollinger, 2003. By a 5-4 vote in the first case and a 6-3 vote in the second, the court upheld a University of Michigan law school program that considered the race of an applicant among several factors, and separately rejected an undergraduate admissions system that automatically gave minorities extra points to boost their chances of acceptance. Justice Sandra Day O'Connor wrote the leading opinion in Grutter v. Bollinger allowing the continuation of race-based affirmative action on campus.

* Fisher v. University of Texas at Austin, 2013. The case was brought by Abigail Fisher, a white suburban Houston woman who asserted she was wrongly rejected by the University of Texas at Austin while minority students with similar grades and test scores were admitted thanks to the school's affirmative action admissions policy. In a 7-1 ruling written by Justice Anthony Kennedy, the court said an appeals court did not apply the correct standard in deciding whether the university's policy violated the U.S. Constitution's guarantee of equal protection. The high court sent the case back to the lower court. Justice Elena Kagan did not take part in the ruling.

(Reporting by Joan Biskupic and Lawrence Hurley; Editing by Howard Goller and Will Dunham)