In the week long fare war to Europe between Oneworld and SkyTeam, another low California fare available through Delta and Virgin Atlantic for Los Angeles LAX to Manchester UK at $486 to $491 round trip for travel from August 2017 to April 2018.
Most low fare itineraries I checked included Skywest Delta-coded flights between LAX and SFO, then Virgin Atlantic SFO to Manchester.
Ticket prices are the same via Delta or Virgin Atlantic websites.
Virgin Atlantic Los Angeles LAX – San Francisco SFO – Manchester MAN – SFO – LAX
Delta Airlines ticket Los Angeles LAX – San Francisco SFO – Manchester MAN – Las Vegas LAS – LAX
Loyalty Traveler – Oneworld LAX/SFO to Paris, Nice, Milan $393-$453, SkyTeam Madrid $446 AUG-APR (June 10, 2017).