Vistara (UK, Delhi International) is in talks with a number of airlines holding slots at London Heathrow airport regarding a potential lease, sources told Indian CNBC TV18.

"However, since slots at such a busy airport are a scarce commodity, we are talking to several carriers to take slots on lease. Simultaneously, we are also looking at London Stansted but we are trying to get Heathrow," an unnamed source said.

The Indian carrier, a joint venture of Tata Sons and Singapore Airlines Group, is expecting to take its first four B787-9s in 2020, allowing it to launch long-haul operations. The deliveries of the first two units are tentatively scheduled for February and March 2020. It has six B787-9s on firm order from Boeing but expects to add additional units from lessors, the ch-aviation fleets module shows.

Besides London, Vistara will target other destinations in Europe and in the Far East in the first phase of its long-haul expansion. Going forward, it also plans to add services to Australia and North America.

According to the ch-aviation schedules module, the India-London market is already extensively served with scheduled passenger flights from Ahmedabad (Air India), Amritsar (Air India), Bangalore International (Air India and British Airways), Chennai (British Airways), Delhi International (Air India, British Airways, and Virgin Atlantic), Hyderabad International (British Airways), and Mumbai International (Air India, British Airways, and Virgin Atlantic). All of these flights serve Heathrow with the exception of Air India's services from Amritsar, which serve Stansted. Air India also plans to add a three times weekly Mumbai-Stansted service from February 20. Other airports in the London metro area do not have scheduled services to India, although TUI Airways operates scheduled charters from London Gatwick to Goa Dabolim.

For its part, Vistara remains, for the time being, a predominantly domestic airline with less than 5% of its total scheduled capacity deployed internationally. The carrier's network outside India comprises of Bangkok Suvarnabhumi, Singapore Changi, Dubai International, and Colombo International. Vistara plans, however, to focus its growth on international routes, achieving a roughly 50/50 split between domestic and international operations by 2023.

As of now, Vistara's fleet includes thirteen A320-200s, nineteen A320-200neo, and nine B737-800s. It has an order for fifty A320neo Family aircraft, including 13 directly from Airbus and 37 from lessors, with five A320neo and two initial A321-200neo due for delivery in 2020.