Three Lutheran churches, having already agreed to merge, this week also approved closer ties with the Episcopal Church in which the two denominations would recognize each other's ministries and share Holy Communion at the parish level.

The 3-million-member Lutheran Church in America, the American Lutheran Church with 2.4 million members and the 108,000-member Association of Evangelical Lutheran Churches agreed Thursday in separate meetings to the new arrangement with the 2.8-million-member Episcopal Church.

At the Episcopal Convention in New Orleans, the proposal was given overwhelming approval by the House of Bishops. The lay and clergy representatives are widely expected to concur when the proposal comes before the House of Deputies.

The Lutheran Church in America convention was rocked in its closing hours when a lay official who is an executive vice president of Mobil Oil Company, abruptly resigned the church treasury post because of a conflict of interest over a church resolution condemning apartheid in South Africa.

The resolution directed the church to withdraw investment funds from corporations with holdings in South Africa. "You should know," L. Milton Woods of Briarcliff Manor, N.Y., told the stunned gathering, "I am one of the chief decision-makers in one such organization" that does substantial business in South Africa and has more than 1,000 employes there.

Woods, who had just been elected to his third term as treasurer of the church, said he agreed with the intent of the anti-apartheid resolution, adopted nearly unanimously, which he said "made a clear witness of love for all those who suffer under apartheid in South Africa."

But he said he differed over tactics. "The real key is how best to work for justice in South Africa," he said. "You don't do it by abandoning people." Woods said Mobil pays black and white workers in South Africa equally and seeks to train black workers for better jobs and promote them to supervisory posts.