The United Methodist Church today approved a $25 million venture into commercial television to do electronic battle with faith healers and other fundamentalist evangelists who now dominate religious TV.

Plans approved by the church's quadrennial General Conference call for the 9.7-million-member denomination to own and operate a TV station, plowing the profits back into a tax-emempt foundation that will find Methodist-oriented programs to be syndicated nationally on other commercial stations.

Today's vote makes the United Methodist Church, after the Southern Baptist American protestantism's second largest body, the first mainline denomination to go into TV station ownership.

Enabling action to begin fund-raising for the purchase of a station or stations is expected later this week.

In other actions, delegates turned back a resolution to make homosexulaity a barrier to ordination. But they also refused to repeal an action adopted four years ago that bans allocating denomination funds to gay groups or "to promote the acceptance" of homosexuality.

The action on ordination leaves to the local ordaining conference the final decision on a candidate's fitness for the ministry. Sexual orientation would be one criterion for such a judgment.

"The present Discipline [book of church order] provides for consideration of the whole moral character" in evaluating a candidate for ministry, said Bruce Birch of Wesley Theological Seminary in Washington. The proposal to bar homosexuals "would single out a particular characteristic as if it were important," he said.

The Rev. Charles Kaysor of Wilmore, Ky., leader of the denomination's vocal, conservative enangelical wing, predicted that not barring homosexuals from the ministry would cause a "hemorrhaging" of conservatives from the church.

"There are multitudes of people who are just barely hanging on as members," he said. "They are watching the General Conference for some sign or symbol." Today's action "will be the sraw that breaks the camel's back" in their retaining loyalty to the church, he predicted.

Delegates also approved a message to Iran's Ayatollah Ruhollah Khomeini and President Abol Hassan Bani-Sadr. It said that church people in America "hear the agonies of your people; we hear their cries for freedom from foreign domination, from cultural imperalism, from exploitation."

The 110-word message concluded: "In the words of Moses, the liberator, let us say to each other, 'Let my people go.' And let us begin to walk down the long, hard road to reconcilation."

The delegates' decision to go into the lucrative television field breaks ranks with other mainline Protestant denominations that have long maintained that Protestant programs should be produced cooperatively, without a denominational bias, and aired free by stations as part of their public service responsibilities.

In practice, however, groups such as the National Council of Churches have had problems securing public service airtime because of the willingness of the more evangelistic groups to pay for air time.