MOSCOW, Sept 22 (Reuters) - Russian wholesale gasoline Ai-92 grade prices fell by 9.7% to 55,892 roubles ($582) per metric ton on Friday, according to exchange data, following a government ban on fuel exports.

Diesel prices were down by 7.5% to 66,511 roubles per ton, according to the data from the St. Petersburg International Mercantile Exchange (SPIMEX).

Wholesale fuel prices in Russia had been steadily rising this year amid fuel shortages, reaching all-time highs.

In response, Russia on Thursday temporarily banned exports of gasoline and diesel to all countries outside of four ex-Soviet states with immediate effect to help stabilise the domestic market and tackle a fuel crunch.

Russia has exported about 1 million barrels of diesel/gasoil and 130,000 barrels of gasoline per day year to date, according to J.P.Morgan.

First Deputy Energy Minister Pavel Sorokin said on Thursday the ban was indefinite and further government actions would depend on the "saturation" of the market with fuel.

Analysts expect the restrictions to be short-lived.

"We believe the ban indeed will be temporary and last only a couple of weeks, until the harvest concludes in October," J.P. Morgan said in a note to clients.

Citi analysts said they expected the Russian ban to last around six weeks.

(Reporting by Reuters; editing by Jason Neely)