The two flight recorders of the Air-India Boeing 747 that crashed off the Irish coast June 23 are due to arrive in Bombay early Saturday morning, as concern continues in international aviation circles about whether India has sufficient technical expertise and facilities to conduct a thorough examination of the two devices.

According to reports received here, international aviation authorities tried to persuade Indian officials to allow the flight recorders to be examined by British or American authorities because of their greater experience in investigating complex air crashes.

Indian authorities, however, insisted that the voice and flight recorders -- recovered from a depth of more than a mile beneath the Atlantic -- be returned here for at least the initial examination.

Air-India officials acknowledged that the facilities in Bombay can perform only a routine computer analysis of the contents of the two flight recorders' magnetic tapes, which contain the final cockpit voice recordings and readings of flight instruments.

India has said foreign experts may assist in the investigation.

The U.S. National Transportation Safety Board is sending two specialists, and Canadian and British officials also are expected to be observers.

If there are problems with the voice and data recorders and a more sophisticated analysis is needed, they will have to be sent to facilities in other countries that have newer and better equipment, the Press Trust of India quoted Air-India officials as saying.

Most authorities here appear convinced by the circumstanial evidence received so far that the sudden crash was caused by a powerful bomb, probably placed in a forward baggage compartment. All 329 persons aboard perished.

Prime Minister Rajiv Gandhi, a former airline pilot, blamed the crash on a bomb in an interview on British television Tuesday. He added, however, "It has not been established where it came from."

Sikh extremists, who have staged hijackings, assassinations and bombings in the past, are considered the most likely suspects.

Initially, a caller claiming to represent a Sikh group said that it had set a bomb in the plane. But following condemnation of the blast by Sikhs of all political persuasions, even extremist groups denied that they were responsible.

The flight and voice data recorders could tell if the crash was caused by a bomb or by either a structural defect in the plane or human error.

The latter two possibilities have been rated as extremely unlikely by most aviation experts.

The need to pinpoint the cause of the crash to preserve the reputations of Air-India as a carrier and of Boeing as a manufacturer led aviation experts to suggest that India would be better off having the data analyzed by more experienced investigators and in better facilities than are available in this country.

But the head of aviation safety for Air-India, H.S. Khola, was quoted by Press Trust of India as saying in Ireland, "We have all the facilities in Delhi and Bombay to analyze the tapes."