• Alaska Airlines to join American's Atlantic and Pacific Joint Businesses.
• Expansion aims to enhance international travel opportunities and premium experiences.
• Partnership includes American, British Airways, Iberia, Finnair, Aer Lingus, LEVEL, and Japan Airlines.
• Filing for approval and antitrust immunity expected in coming months.

This partnership may indicate a significant expansion of Alaska Airlines' international reach, potentially strengthening its competitive position in the global market. The inclusion in these joint businesses could suggest a shift towards more seamless and integrated travel experiences, which may benefit customers and enhance the airlines' market share.