DALLAS — The Episcopal Diocese of Fort Worth took the first steps Saturday to withdraw from the national church as part of a growing rift over Scriptural interpretation and homosexuality, giving preliminary approval to constitutional amendments.

The conservative diocese is among four of the 110 Episcopal dioceses — including Pittsburgh, San Joaquin, Calif., and Quincy, Ill. — that have approved similar measures to break away and align with an overseas Anglican leader. The dioceses contend U.S. church leadership has wrongly abandoned Scriptural authority and traditional teachings on truth, salvation and the divinity of Jesus Christ.

The Fort Worth convention followed a testy exchange of letters between the national church's presiding bishop, Katharine Jefferts Schori, and the diocese's Bishop Jack Iker.

Jefferts Schori warned Iker that he could face discipline if he continues to back proposals to separate from the U.S. church. Iker responded by accusing her of "aggressive, dictatorial posturing."

Iker referred to her letter again Saturday during his address to the convention, saying that he "must object to the claim that the presiding bishop has any canonical authority in this diocese or any legitimate power over the leadership of this diocese."

A series of amendments relating to the split passed overwhelmingly, including an amendment that deleted reference to the authority of the Episcopal Church and replaced it with the Anglican Communion. That measure passed in votes of 69-14 by clergy and 95-28 by lay delegates.

Iker said the decision showed firm resolve about moving forward. He said that he recognized that not everyone fully supported the decision, but that the debate was characterized by respect and honesty.

The measures will be up for final approval next year.

The convention said the diocese wishes "to remain within the family of the Anglican Communion while dissociating itself from the moral, theological, and disciplinary innovations of the Episcopal Church."

A majority of the 77 million-member Anglican Communion holds traditional views that homosexuality is condemned by Scripture, while a majority in the Episcopal Church do not.

The division between conservatives and the Episcopal Church, the Anglican body in the U.S., has sharpened since the denomination consecrated New Hampshire Bishop V. Gene Robinson, who is openly gay, in 2003.

The Episcopalians are among several denominations struggling to agree on what the Bible says about gender and sexuality.