LONDON, May 27 (Reuters) - Northwest European gasoline refinery margins fell to $21.25 a barrel on Wednesday despite worries around fuels due to the Middle East conflict.

• About 24,000 metric tons of E5 gasoline barges traded in the Argus window as BP and Exxon sold to TotalEnergies.

• No E10 gasoline barges traded in the session.

• U.S. President Donald Trump's waivers allowing foreign-flagged ships to move oil and fuel between U.S. ports have had little impact on high domestic gasoline prices due to elevated shipping rates and the relatively small fuel volumes transported so far, a Reuters analysis found.

• Japan's industry ministry said the benchmark for calculating gasoline price subsidies would switch back to Dubai crude prices from Brent crude from next week, as the gap between Brent crude and Dubai crude has narrowed.

• Oil major TotalEnergies said it would extend its policy of capping fuel prices at its French service stations through the month of June as the Middle East crisis continues.

• Meanwhile, EU-27 and UK gasoline and blending component exports have averaged 788,000 barrels per day so far this month, compared with an average of 961,000 bpd in April, Kpler data showed.