The owners of London City Airport have selected Credit Suisse to advise them on a sale, insiders have told Reuters.

The Wharf based bank and the majority owner Global Infrastructure Partners (GIP) have declined to comment but Credit Suisse was one of the founding businesses of GIP in 2006 along with General Electric Co.

The company bought the airport in the London’s Docklands for £742million and holds a 75% stake. Oaktree Capital Management holds the rest and both are minded to look for a quick sale – possibly by the end of the year – as there is a “prime market” for small airports which offer stable returns.

The sale – which could raise £2bn – comes at a time of mixed fortunes for the airport. Its passenger numbers have reached record highs following a move to mix tourist destination in with its usual roster of business routes.

But much of its planned major expansion is on hold, having been blocked by the Mayor Of London, despite receiving approval from the Newham Council. The airport is currently appealing the decision and is expecting to hear the result next year.

The airport saw 406,968 passengers in July – its busiest ever month in its near 28-year history.

This is 30,000 higher on the previous best of 379,020 set in March, and an 18.8% increase on July 2014. The airport expects to top four million passengers over the year.

Chief executive officer Declan Collier said: “These record figures underline that we must be allowed to grow. The £16million plan to transform our Western Pier departure gates will provide huge benefits when complete in autumn 2016, but it is only a small step on the journey.

“It is critical that we are allowed to proceed with our City Airport Development Plan (CADP) that will deliver better infrastructure, better facilities for our airlines, and a better passenger experience.”

The plans, which include building a parallel taxi lane and seven new aircraft stands, will provide vital London airport capacity, create 1,500 jobs and generate £1.5billion annually for the UK economy by 2023.