LONDON (Bloomberg) - British Airways plc., Europe's third- largest airline, plans to lease 23 aircraft and crews from other European carriers should flight attendants strike in a dispute over staffing levels, CEO Willie Walsh said.

British Airways would operate a "substantial proportion" of long-haul services and a "good number" of short-haul flights in the event of a walkout, Walsh said in an e-mail sent to employees on Wednesday. He did not identify the other airlines.

The carrier faces its first strike since 1997 after failing to resolve a dispute with cabin crew over the number of flight attendants assigned to some intercontinental flights. The Unite labor union won backing for a stoppage after a month-long ballot that ended February 22 and can call a walkout at seven days' notice within 28 days of that date.

The airline has also arranged to book seats on carriers to enable passengers to reach their destinations, Walsh said. London-based British Airways has trained 1,000 other employees for cabin-crew work if a strike takes place, and will continue to prepare potential replacements at least this month, he said.