WASHINGTON, Oct 21 (Reuters) - Dozens of U.S.

Representatives from both political parties urged the Biden

administration to toughen sanctions on Russian oil shipments and

questioned an exception issued to the world's largest oilfield

company SLB to operate in the country.

Since Russia's 2022 invasion of Ukraine, the U.S. and

European countries have sought to cut Moscow's energy revenue

for fighting the war through sanctions. That prompted several

oilfield service companies to leave Russia but SLB has remained

operating in the country, helping keep Russian oil production

flowing.

The 52 lawmakers, including Democratic Representatives Jake

Auchincloss and Lloyd Doggett and Republican Representative

Brian Fitzpatrick, said that since the invasion in February

2022, SLB has signed new contracts, recruited hundreds of staff,

and imported nearly $18 million in equipment into Russia.

"This U.S.-based company is keeping (Russian President)

Vladimir Putin's war machine well-oiled with financing for the

barbaric invasion of Ukraine. We urge you to continue supporting

our Ukrainian allies by pursuing more rigorous oil sanctions to

effectively restrict Putin's profits," the lawmakers said in a

letter to Treasury Secretary Janet Yellen and Secretary of State

Antony Blinken.

The departments of Treasury and State did not immediately

respond to requests for comment. SLB did not immediately respond

to a request for comment.

The lawmakers said President Joe Biden's administration has

pointed to a Treasury Department general license that authorizes

U.S. persons to process energy-related transactions that

involves certain sanctioned Russian financial institutions.

"We are cognizant of the arguments often cited that

Russian oil provides a critical and irreplaceable segment of the

global oil supply," the lawmakers said. "However, allowing

Russia to benefit from Western technology and expertise only

increases the resiliency of their oil and gas sector against

Western sanctions and prolongs its ability to finance its

illegal offensive."

In May, Assistant Secretary of State Geoffrey Pyatt told

Reuters that SLB had not violated sanctions against Russia.

SLB last year received 5% of its revenue from Russia. It had

10,000 employees in Russia helping energy firms pump oil and gas

when the war began in 2022.