(Reuters) — The world’s largest aircraft lessor Aercap said Wednesday said it was still calculating the impairment charge it will have to take on $3.3 billion worth of aircraft leased to Russia but said it would be “manageable.”

Lessors had until Monday to wind up current rental contracts in Russia under sanctions imposed by the European Union after Moscow's invasion of Ukraine, leaving them facing heavy potential write-downs or a long insurance battle.

The Dublin-based lessor, which had 5% of its fleet by net book value leased in Russia at the end of 2021, had the largest exposure of any lessor to Russia when the sanctions were introduced.

“We expect to recognize an impairment on our assets in Russia that have not been returned to us as early as the first quarter of 2022, although we have not determined the amount of any impairment,” Aercap said in a statement on its results for the final three months of 2021.

Aercap had 135 owned aircraft and 14 owned engines on lease to Russia with a net carrying value of around $3.1 billion. It has since repossessed and removed 22 aircraft and three engines, with a net carrying value of around $400 million, it said.

The company also has letters of credit related to aircraft and engines leased in Russia worth around $260 million, of which it has received around $175 million to date, it said.

Although most leased planes are insured, the unprecedented nature and scale of the potential losses will likely mean years of litigation between lessors and insurers before any decisions on payouts are made, analysts say.

The CEO of rival Avolon on Tuesday said Russian airlines could be frozen out of the aircraft leasing market well beyond the Ukraine conflict, closing off what had been a strong market for the sector.

Aercap, by far the largest aircraft lessor in the world after its acquisition last year of rival GECAS, had 3,701 aircraft, engines and helicopters on its books at the end of last year, it said.

It earned net income for 2021 of $1.001 billion and said the rapid recovery of the airline industry following the easing of COVID-19 restrictions put it “on a positive trajectory heading into 2022.”