Ronald Reagan, the conspicuous absentee from the Iowa debates, yesterday that he has agreed to meet his GOP rivals face-to-face in a South Carolina forum next month.

Reagan told reporters in South Carolina that he had agreed to a debate at the University of South Carolina in Columbia Feb. 28, before that state's March 8 Republican primary, the first GOP test in the South. t

Reagan had been critized for his failure to participate in the Iowa debates with other GOP presidential hopefuls. In that first campaign test, the caucuses, Reagan was upset by former ambassador George Bush.

He also has been invited to participate in a debate in New Hampshire Feb. 21, but said he did not know if he would accept.

The South Carolina debate will be held at the university's Longstreet Theater. So far, Sen. Howard H. Baker Jr. of Tennessee and John B. Connally have said they will particcipate.

Bush eagerly accepted the opportunity to debate Reagan in South Carolina, saying, "I am sure we can work something out. We've always been in favor of a debate."

Bush also announced that he has accepted the invitations to participate in two debates in New Hampshire. The first, sponsored by the League of Women Voters, is to be held Feb. 20 in Concord. There is no date set for the second, a proposed one-on-one clash between Bush and Reagan, sponsored by The Nashua Telegraph.