Pakvisit>International Airlines of the World

All of the following are "official" airline sites. There are many more, maintained by travel agencies, individuals et al. 

Antigua:

Caribbean Star Airlines Ltd.

Australia:                                                                                                                   

Ansett Australia - Flight West Airlines - Kendell Airlines - Qantas -

Southern Australia Airlines

Belgium:

Citybird Airlines - Sabena

Belize:

Maya Airways

Bhutan:

Druk Air

Brazil:

 Varig - Vasp

Bulgaria:

Canada:

Air Canada - Air Labrador - Pacific Coastal Airlines - Timberline Air

Caribbean:

Carib Aviation - Air Aruba - Air Jamaica - Cayman Airways -

Island Air

China:

Colombia:

          Intercontinental de Aviacion

Costa Rica:

Aero Costa Rica - Lacsa

Denmark:

Maersk Air - SAS

Fiji:

 Air Fiji - Air Pacific - Sunflower Airlines 

Finland:

 Finnair

France:

 Air France - Corsair - TAT

Germany:

 Aero Lloyd - Deutsche BA - LTU - Lufthansa

Greece:

 Air Greece

Greenland:

 Greenlandair - SAS

Guatemala:

 Aviateca Airlines

 

Honduras:

 Taca Int. Airlines

Hong Kong:

 Cathay Pacific Airways (Worldwide) - Cathay Pacific Airways (Hong Kong)

Hungary:

 Malev Hungarian Airlines

Iceland:

 Air Atlanta Icelandic - Air Charter Icelandic

Indonesia:

Ireland:

 Aer Lingus

Israel:

 Arkia - El Al

Italy:

 Air Dolomiti - Air One - Alitalia

Japan:

 All Nippon AW - Cathay Pacific Airways (Japan) - Japan Airlines (JAL) - Japan Air Systems

Jordan:

Lithuania:

Air Lithuania

Luxembourg:

Macau:

Malaysia:

Malta:

Maritius:

Air Mauritius

Mexico:

 Mexicana

Netherlands:

 KLM

New Caledonia:

 Air Caledonie International

Nicaragua:

 Nica Airlines

Norway:

 Braathens SAFE - SAS

Panama:

 Copa Airlines

Peru:

 Aeroperu

Philippines:

 Philippine Airlines

Portugal:

 Portugalia Airlines - TAP Air Portugal

Russia:

 Aeroflot

Samoa:

Polynesian Airlines

St. Kitts and Nevis:

 Nevis Express Ltd

Solomon Islands:

 Solomon Airlines

El Salvador:

Taca

Saudi Arabia:

Saudi Arabian Airlines

Singapore:

Singapore Airlines

Slovenia:

 Adria

South Africa:

 SAA - South African Express

South Korea:

 Asiana - Korean Air

South Pacific (General):

 Pacific Islands

Spain:

Air Europa - Iberia - Spanair 

Sweden:

SAS

Switzerland:

Air Engiadina - ASA Aerospace - Swissair

Taiwan:

 Mandarin Airlines

United Arab Emirates:

 Emirates Airlines - Gulf Air 

UK:

 Air UK - British Midland - Brymon - CityFlyer - GB Airways -

British European - Loganair - Virgin Atlantic

US:

 Alaska - American Airlines - America West - ATA, Inc -

COMAIR (the Delta Connection) - Continental - Delta - Frontier -

New England - Northwest - RenoAir - Southwest - Tower Air -

TWA - United - US Airways - Yute Air Alaska

Vanuatu:

 Air Vanuatu

Western Samoa:

 Polynesian Airlines