The recommendation comes a month after the church's highest court ruled that congregations may conduct religious ceremonies celebrating gay unions that stop short of marriage.
A 25-22 vote recommending the ban followed impassioned testimony on proposed amendments to the Book of Order, the church constitution, before the Committee on Physical and Spiritual Well-being.
If the 560-member assembly, the chief policy-setting body for the 2.6 million-member Presbyterian Church (U.S.A.), passes the amendment during its meeting here this week, approval must then be sought from ordained ministers and elders nationwide.
Two ministers and an elder argued for the ban on grounds that permitting individual churches to perform blessing ceremonies for gay and lesbian couples, even if the services stop short of marriage, implies that the church condones same-sex relations.
The General Assembly approved a ban on same-sex unions in 1995, but that amendment failed to win ratification by the nationwide presbyteries.
Issues involving the role of homosexuals in the church were brought to the forefront of the annual meeting when gay and lesbian activists and supporters demonstrated outside Sunday's opening gathering.
Supporters of same-sex unions were disappointed.
"This was a chance for us to say we believe in families, we believe in couples and relationships, and we didn't take it," said Katie Morrison, 28, of Oakland, a gay candidate for the ministry.
The recommended amendment states that church officers may not perform such ceremonies and they cannot be conducted on church property or use church resources.
A proposal to allow individual ministers to make their own choices on the matter was defeated 26-20, and a resolution for the church to support civil legislation to enact laws permitting same-sex unions was defeated 29-17.
Opponents of same-sex blessings told the panel that allowing the practice to continue as a "friendly blessing" would be akin to performing civil union ceremonies for polygamists.
"We cannot bless an act or behavior that we also call a sin," said Elder Ed Gobel of the Tampa Bay Presbytery in Florida, which proposed one of the three amendments.
The Presbyterian Church (U.S.A.) prohibits gays and lesbians from marrying within the church or serving as ministers, but it does not exclude them from practicing the faith.
The Rev. Bruce Powell of the Charlotte, N.C., Presbytery argued that church officials should not view banning same-sex unions as an act of prejudice.
"Some will accuse us of being exclusive because of fear, anger, and even hatred," Powell said. "Please don't believe this rhetoric because it's not true. The issue is biblical authority."
The Rev. Tricia Dykers Koenig of the Western Reserve Presbytery argued that ministers should be able to decide for themselves whether to bless gay and lesbian couples.
She said predominantly homosexual congregations could disappear if recognition of their relationships was prohibited.