JERUSALEM: Israel's El Al airlines is seeking to put an immediate end to its weekly flight to Cairo for the first time since the signing of the 1979 peace treaty with Egypt, the Maariv newspaper reported on Sunday.

The plans were laid out in a letter sent by El Al's chief executive to Israeli Foreign Minister Avigdor Lieberman, which pointed to heavy security requirements and high operational costs, rendering it not economically viable.

"Operating the flight route to Cairo and maintaining the necessary infrastructure for that requires a large amount of security and operational resources, and heavy economic expenditure which amounts to hundreds of thousands of dollars annually," wrote CEO Eliezer Shakedi.

"Without any commercial justification and in light of the high economic cost of operating this line, El Al cannot continue to bear these heavy expenses, and therefore is intending to stop operating the route to Cairo immediately," said the letter, excerpts of which were published in Maariv.

The airline was not immediately available to comment on the report, but a spokesman for Lieberman confirmed receiving the letter. "The matter is being looked into," Irena Etinger told AFP.

El Al has been flying the route between Tel Aviv and Cairo for more than three decades, running at least one flight per week, Maariv said.

But since the overthrow of president Hosni Mubarak in February 2011 and the unrest which followed, the airline decided to operate the service on a reduced basis according to commercial needs in order to fulfil government demands, Shakedi wrote.

The flights, he said, were almost empty, and if the airline were to continue operating them, it would need assurances about which government body would help foot the bill.

"In a situation like this, and given the sensitive security situation in Egypt, El Al would have to make special arrangements which would have substantial costs," he wrote.

In light of Israel's strained ties with Egypt's new Islamic President Mohammed Morsi, the foreign ministry fears the flights may never be reinstated.

"Any element of normalisation between the two countries that is stopped, simply won't be reinstated," a ministry source told the paper.

Although the two neighbours signed a peace treaty in 1979 the relationship has never been warm, and the rise of a new Islamist-dominated government in Cairo following the overthrow of the Mubarak regime has raised fears in Israel over the future of the landmark agreement.