JERUSALEM, May 18 (Reuters) - Israeli airline El Al said on Wednesday it had narrowed its first-quarter loss, with passenger numbers returning to pre-COVID levels after Israel's borders were reopened to foreign tourists.

El Al, Israel's flag carrier, said it lost $66 million in the first three months of 2022, versus a loss of $86 million a year earlier. Revenue more than doubled to $283 million, though a sharp rise in expenses offset most of the gain, it added.

Shares in the airline were down 2.7% at 0856 GMT in Tel Aviv.

Sales had plummeted at El Al amid restrictions imposed during the pandemic to curb the spread of COVID-19, but borders were fully opened in March. Its load factor rose to 73% in the quarter from 53% in the January to March period of 2021.

El Al, which has a 22% market share at Ben Gurion Airport near Tel Aviv, estimated that sales in May reached $267 million, up 10% from May 2019 levels.

In recent weeks El Al, which has an all-Boeing fleet of 45 aircraft, has had to cancel a number of flights due to staffing issues.

"The return to routine is hitting all airlines in the world, which are experiencing high demand and being forced to fill qualifications and manpower gaps," said incoming chief executive Dina Ben Tal.

She noted that El Al, which was forced to lay off one-third of its staff as part of a government bailout package, will train new employees and return to a full fleet of aircraft gradually.

"We have a lot of work to do on this matter," said Ben Tal, who is succeeding Avigal Soreq.

El Al also said it remained in negotiations with insurer Phoenix Group for a $130 million loan, with talks expected to be completed by the end of June. (Reporting by Steven Scheer; Editing by Jan Harvey)