WASHINGTON, March 20 (Reuters) - The Trump

administration said on Friday it has lent 45.2 million barrels

of crude oil from the Strategic Petroleum Reserve to oil

companies, in an attempt to control prices that have spiked to

four-year highs due to the war on Iran.

The initial batch covers 52% of the up to 86 million barrels

the administration announced last week it planned to lend.

Ultimately the U.S. aims to lend 172 million barrels for

delivery throughout this year and into next.

Companies awarded the initial SPR loans include BP Products

North America, Gunvor USA, Marathon Petroleum ( MPC ) and Shell

Trading, the Energy Department said in a statement.

The loans are part of an agreement with 32 countries in the

International Energy Agency to release 400 million barrels of

oil from reserves. The war launched by the U.S. and Israel on

February 28 has pushed crude prices to their highest since the

start of Russia's invasion of Ukraine.

Companies will return the oil with extra barrels as a

premium, a system the Energy Department says was meant to

stabilize markets "at no cost to American taxpayers." The

structure of the swap is unusual in that it required companies

to pay a premium of 18% to 22% in oil. Bidders could offer to

pay back even more oil in hopes of ​winning contracts.

The process will eventually add nearly 10 million barrels to

the SPR for the first batch, the department said.

Other companies that have been awarded contracts as of

Friday are Energy Transfer Crude Marketing, Mercuria Energy

America, Trafigura Trading and Vitol.

The SPR, held in underground caverns on the Texas and

Louisiana coasts, holds about 415 million barrels of crude, more

than the world uses in four days.

The U.S. aims eventually to exchange 172 million barrels

from the SPR, and expects oil companies to return about 200

million barrels, including the premium.