Star Alliance member airline Air India has $542 round trip ticket prices for Newark EWR to London Heathrow nonstop for flights from November to March. These tickets book in Air India Economy E class, a fare class earning 50% flight miles with United Mileage Plus and Aeroplan. These tickets are searchable on Google Flights, however, the low fares are more prevalent with online travel agency sites like Orbitz.com compared to ticket prices I found on Air India.
Air India has 3x weekly service on Mon, Wed, Fri and $542 fares are available from Nov 9 to March 8.
Air India Newark EWR – London Heathrow LHR