MINNEAPOLIS (AP) _ The General Assembly of the Presbyterian Church (U.S.A.) voted Tuesday to reaffirm the church's pro-choice stand on abortion.

By a 281-to-266 margin, church commissioners voting at the group's annual meeting in Minneapolis rejected a measure which would have commissioned a study to reconsider opinions on the abortion issue.

''We've taken another step in the wrong direction by not taking seriously enough the diversity within our denomination on the issue,'' the Rev. Bart Tarman, a director of Presbyterian Pro-Life, said at a news conference after the vote.

Tarman, of Santa Barbara, Calif., said the assembly ''has missed a dynamic oportunity to reconsider the church's abortion position.''

The Rev. Bob Emrich of Saginaw, Mich., said the vote ''absolutely reaffirmed the traditional Presbyterian position.''

''One of the hallmarks of Presbyterianism is that God alone is Lord of the conscience,'' said Emrich. ''It's not just about abortion, because there are people who believe abortion is wrong. But they don't want to limit people's freedom of conscience.''

The assembly represents the largest Presbyterian denomination in the United States, with more than 3.1 million members.

Tarman said that ''80 percent of the denomination favors some modification in our (abortion) position.''

Emrich disagreed, saying, ''I do think they (pro-life advocates) are a minority.''