At the moment, no airlines fly direct between Amritsar and London.
It takes about 8 hours and 10 minutes to fly from London to Delhi direct. There are different airlines that take this route with most of them recording the same flight time.
The airlines which provide this service are Lufthansa, Swiss Airlines.
The airlines that fly from New York to Luton Airport in London are American Airlines and United Airlines. These can be booked on Expedia.com.
Nairobi Airlines
American Airlines and Hawaiian Airlines fly direct between Phoenix and Honolulu.
Alitalia is one major airline that goes to Venice, Florida.
Qatar Airlines via Doha
This list may not be complete, but these airlines fly non-stop from Madrid to Venice, Italy: Alitalia and KLM Royal Dutch Airlines.
British Airways, Finnair, Scandinavian Airlines,
British Airways fly direct from Houston to London(Heathrow) Air France fly direct from Houston to Paris(Charles De Gaulle) KLM fly direct from Houston Amsterdam(Schipol) Lufthansa fly direct from Houston Frankfurt(Int) Continental flys nonstop to Frankfurt Amsterdam Paris London
Alaska airlines and i think southwest