LONDON, June 23 (Reuters) - Northwest European gasoline refining margins fell $2.4 to $28.70 a barrel on Tuesday after sharp gains in the previous session, but remained underpinned by tighter supplies.

• Around 10,000 metric tons of Eurobob E10 gasoline barges were traded in the Argus window, with TotalEnergies and Trafigura selling to Exxon Mobil, Trafigura, BP and Varo across five deals.

• An additional 14,000 tons of Eurobob E5 gasoline barges were also traded, with BP and Exxon selling to TotalEnergies.

• Russia is considering a diesel export ban, Deputy Prime Minister Alexander Novak said on Tuesday, while a newspaper reported on possible fuel imports to tackle shortages, especially in Crimea, which tightened restrictions on public services and activities.

• EU-27 and UK gasoline and blending component exports to other regions have averaged 915,000 barrels per day so far this month, from an average of 874,000 bpd for the whole of May, Kpler data showed.