Ultra-Orthodox Jews make up more than 25% of El Al's customers

The airline recently broke its practice of not flying on the holy day after delays left passengers stranded.

But Israel's ultra-Orthodox community wants a legally binding document promising it will not happen again.

The community - which accounts for more than a quarter of the airline's passengers - has threatened a boycott.

Concessions

The airline angered the community by making several flights after sunset on Friday - the beginning of the Jewish Sabbath - in an attempt to catch up after an airport workers' strike.

"El Al does not fly in principle on the Sabbath but there have been instances that it is forced to move passengers and has done so," the company said in a statement.

The company's chief executive has pledged not to desecrate the Sabbath again in private meetings with ultra-Orthodox leaders.

But the Israeli media reports that the airline may be considering signing a written commitment.

The group's concessions to ultra-Orthodox Jews have been rewarded with a greater share of their custom than rival airlines.

They get special meals, seats far from potentially offensive in-flight films, access to religious readings and informal prayer meetings normally allowed to continue undisturbed.