El Al Shares Tumble After Regulator Blocks Merger With Israir

El Al Israel Airlines shares tumbled after a regulator blocked a merger with a budget carrier that the company was counting on to boost revenue.

Israel’s Antitrust Authority rejected El Al’s planned $24 million takeover of Israir Airlines & Tourism Ltd., which offers discount flights and tourism packages, on the grounds that it would corner too much of the local demand for domestic and international flights, according to a statement Wednesday. El Al management had touted the deal as a way to diversify away from its core business, which has been under pressure from low-cost carriers.

The Israir setback is ...