The following airlines serve Los Angeles LAX Airport.
Airline Terminal
Aeroflot, SU Main Terminal
Aerolitoral, 5D Terminal 5
Aeromexico, AM Terminal 5
Air Canada, AC Terminal 2
Air Canada Jazz, QK Terminal 2
Air China International, CA Terminal 2
Air France, AF Terminal 2
Air Jamaica, JM Terminal 5
Air Midwest, ZV Terminal 4
Air New Zealand, NZ Terminal 2
Air Pacific, FJ Main Terminal
Air Tahiti Nui, TN Main Terminal
AirTran Airways, FL Terminal 6
Alaska Airlines, AS Main Terminal
Alitalia, AZ Terminal 5
American Eagle, MQ Terminal 4
ANA, NH Main Terminal
Asiana Airlines, OZ Main Terminal
Austrian, OS Terminal 3
British Airways, BA Main Terminal
Cathay Pacific Airways, CX Main Terminal
China Airlines, CI Main Terminal
Continental Airlines, CO Terminal 6
COPA, CM Main Terminal
Delta Air Lines, DL Terminal 5
El Al, LY Main Terminal
Emirates, EK Main Terminal
EVA Air, BR Main Terminal
Frontier Airlines, F9 Terminal 6
Hawaiian Airlines, HA Terminal 2
Horizon Air, QX Terminal 3
JAL, JL Main Terminal
KLM, KL Terminal 2
Korean Air Lines, KE Main Terminal
LACSA, LR Terminal 2
Lan Airlines, LA Main Terminal
Lan Peru, LP Main Terminal
LTU International Airways, LT Main Terminal
Lufthansa, LH Main Terminal
Malaysia Airline, MH Main Terminal
Mexicana, MX Main Terminal
Northwest Airlines, NW Terminal 2
Qantas Airways, QF Main Terminal
Singapore Airlines, SQ Main Terminal
Southwest Airlines, WN Main Terminal
Spirit Airlines, NK Terminal 6
Sun Country Airlines, SY Terminal 6
SWISS, LX Main Terminal
TACA, TA Terminal 2
Thai Airways International, TG Main Terminal
United Airlines, UA Terminal 6
US Airways, US Terminal 1
Virgin America, vx Terminal 3
Virgin Atlantic Airways, VS Terminal 2
WestJet, WS Terminal 2

More details on airlines from the Los Angeles Airport website.

Los Angeles LAX Terminal map.