President Carter yesterday nominated the first Hispanic and a woman attorney to fill two vacancies on the D.C. Superior Court.

Ricardo M. Urbina, 34, a law professor at Howard University, and Dorothy Sellers, 37, a private Washington lawyer, were selected from a group of six possibilities sent to the White House by the D.C. Judicial Nominating Commission.

In choosing the two, Carter passed over the top prosecutor in the U.S. attorney's office for Superior Court Operations, Henry F. Greene, who had been strongly supported by some of the city's legal establishment, the U.S. attorney's office and some Justice Department officials.

The two choices to fill the seats vacated by former Superior Court Judge Norma H. Johnson and the late Edmund T. Daly must be confimed by Congress.

The selections of Urbina, which comes during National Hispanic Week proclaimed by Carter, and Sellers continued to fit the pattern of Carter's previous Superior Court choices. He has now chosen 17 of the 43 judges on the court, including 11 minorities and women.

However, Congress is expected to adjourn in a few weeks and there may not be enough time for the selections to be confirmed. Depending on the outcome of the presidential election Nov. 4, the nominations could be resubmitted when Congress reconvenes.

Urbina heads the Howard University Law School Criminal Justice Program, in which students litigate criminal misdemeanor cases in D.c. Superior Court.

Urbina also has full-time teaching responsibilities at the law school. From 1970-72 he was an attorney with the District's Public Defender Service, and practiced law privately from 1972 to 1973. Born in New York City, Urbina received degrees from Georgetown University and Georgetown University Law Center.

"My reaction to the appointment is that it's been a very gratifying experience in knowing that I qualified for the nomination," Urbina said late yesterday. Urbina, who would be the third lawyer to join the bench from the public defender's service if confirmed, was an all-American track star in college and high school.

Sellers is a partner at the D.C. law firm of Melrod, Redman and Gartlan where she specializes in commercial litigation. She also has worked on cases for the American Civil Liberties Union and the Women's Legal Defense Fund.

Sellers, who graduated from George Washington Law School, clerked for the U.S. Court of Appeals for the District of Columbia Circuit in 1969. Sellers was born in Grand Rapids, Mich.

Urbina was named to fill the seat of Norma H. Johnson, who was appointed to the federal bench last February. Sellers fills the seat formerly occupied by the late Edmund Daly, who died on June 27 of this year.

The nominations must be considered by the Senate Subcommittee on Governmental Efficiency and the District of Columbia. A committee source said yesterday that with Congress about to leave town in several weeks, it was difficult to say if there would be time to confirm the choices.

The committee source said that other judicial nominations were already being held up by some Republican senators, and "there is some question and confusion as to whether these will go through." However, because the choices are for the local superior court and not a federal court, it is possible they could be approved without too much controversy.

According to sources, the other attorneys under consideration by the president besides Greene were assistant U.S. attorney's Donald L. Golden and Diane Sullivan and Robert Tignor.

Greene, who has been passed over three times now for a judgeship, was considered a possibly controversial choice because he was instrumental in bottling up the reappointment of former Superior Court Judge Charles Halleck, an action which resulted in Halleck's leaving the bench. Had Greene been nominated, some observers felt his choice would have been equally controversial and might have had difficulty getting through.