Avolon, which is backed by private equity firms Cinven Ltd, CVC Capital Partners Ltd and Oak Hill Capital Partners, as well as Singapore's sovereign wealth fund, has been interviewing investment banks in the last few weeks to hire underwriters for an IPO, the sources said on Thursday.

CVC and Cinven declined to comment. Representatives of Avolon and its other investors did not immediately respond to requests for comment. The sources asked not to be identified because the matter is not public.

Avolon's listing plans come as aviation draws interest from longer-term investors such as insurers and pension funds, who hope to boost weak returns dictated by low interest rates.

Avolon, which is based in Dublin, has raised $7.2 billion (4.3 billion pounds) in capital since its launch in May 2010.

It provides aircraft leasing and lease management services to airlines and aircraft investors. It has a fleet of more than 190 aircraft serving 46 customers in 27 countries.

Its customers include American Airlines Group Inc (>> American Airlines Group Inc), Air France KLM SA (>> AIR FRANCE-KLM) and Ryanair Holdings Pc (>> Ryanair Holdings plc).

Avolon's focus is on young and fuel-efficient single-aisle aircraft made by Boeing Co (>> The Boeing Company) and Airbus Group NV (>> AIRBUS GROUP). In 2013, it delivered a total of 34 aircraft to its customers valued at more than $2 billion.

Avalon's shareholders have made equity commitments to the company totalling $1.4 billion since its launch, according to its website. It has also raised $5.8 billion in debt from commercial and specialist aviation banks.

(Reporting by Soyoung Kim and Greg Roumeliotis in New York; Editing by Bernard Orr)

By Soyoung Kim and Greg Roumeliotis