BP is offloading its 20% stake in Russian oil giant Rosneft due to the crisis in Ukraine.

It’s one of the first major moves by a big company after the invasion and it’s a rapid, costly end for BP to nearly three decades of operating in Russia.

Losing Rosneft means BP loses around half its oil and gas reserves, and the British company says it will take a financial hit of up to 25 billion

In a Sunday statement, BP chief executive Bernard Looney said:

"I have been deeply shocked and saddened by the situation unfolding in Ukraine and my heart goes out to everyone affected. It has caused us to fundamentally rethink bp's position with Rosneft."

Looney and his predecessor Bob Dudley will both step down from the board of Rosneft.

BP is Russia’s biggest foreign investor and its move puts the spotlight on other Western companies with operations there including France's TotalEnergies and Britain's Shell.

It also underscores growing pressure from Western governments on companies to cut back Russian operations.

Russian news agencies reported that Rosneft had blamed BP's decision on "unprecedented political pressure."