President Carter yesterday nominated for U.S. District Court judgeships two Maryland state judges who would upon confirmation by the Senate become the first black and the first woman to serve on the federal bench in the state.

Joseph C. Howard and Shirley B. Jones had been recommended by Sen. Paul S. Sarbanes (D-Md.), who hailed yesterday's announcement from the White House as "excellent."

Sarbanes said Howard and Jones "will bring strength and quality to the federal bench." The senator added that the nominees are "seasoned trial judges of outstanding ability, character and intergrity."

Howard, 56, upset tradition when he ran against a sitting judge and was elected to a 15-year term on the Supreme Bench in 1968. He has been an adviser to the NAACP and CORE, as well as to the black caucus in the state legislature and Rep. Parren J. Mitchell (D-Md.).

In 1961, Jones was the first woman named to the Supreme Bench. She was admitted to the bar at age 22, after graduating with highest honors from the University of Baltimore Law School. After working in various governmental positions, she was named to the Orphans Court in 1959. Jones, 53, is a native of Cambridge, Md.

The nominations of Howard and Jones are consistent with the president's off-stated desire to increase minority and female representation on the federal bench. However, Sarbanes chose to ignore the president's suggestion that potential candidates be selected by citizen panels.

Despite Sarbanes' refusal to depart from the tradition that allows the state's senior senator to handpick candidates for the federal bench, his recommendations of Howard and Jones last January were hailed by several lawyer's organizations and citizens' groups.

In Virginia, where four new judgeships have been created, the state's senior senator, Harry F. Byrd Jr., an independent, followed Carter's recommendation and named citizen panels.

The panels then recommended 10 white males for the new positions. As the result of Byrd's refusal to expand the list to include minority and female representation, an impasse has developed in the nomination process in that state.