Specific details could not be immediately ascertained and there were no immediate comments from Air India about the deals.
The Tata group-owned Air India is expanding its operations as well as it's fleet.
On January 27, Air India chief Campbell Wilson said the airline is finalising a historic order of new aircraft.
Air India, earlier under the ownership of the government, had acquired new aircraft more than 16 years ago.
It has not purchased a single aircraft since 2005 and the last order was for 111 aircraft -- 68 with Boeing Co and the remaining 43 with Airbus -- and that deal was worth USD 10.8 billion.
The source told PTI that the deal with Airbus for around 250 planes has been finalised and the announcement is likely next week.
The deal is likely to include 40 wide-body Airbus A350s and Air India will be the first Indian carrier to operate the aircraft.
In the past, Air India had operated wide-body A330s.
On Wednesday, aviation consultancy CAPA said Indian carriers are likely to place orders for up to 1,700 planes by 2024 and Air India may make the first move with some 500 planes ordered.
Currently, Indian carriers operate less than 50 wide-body aircraft, an insignificant number for such a significant market. In contrast, Emirates alone has a fleet of over 260 wide bodies, CAPA had said.
Recently, IndiGo started wide-body operations on the India-Turkey route with a wet-leased B777 and plans to induct two more such planes.