June 5 (Reuters) - Russia's finance ministry said on Wednesday it would reduce its purchases of foreign currency and gold in the month ahead, a move that will increase the state's overall forex sales.

The finance ministry said its purchases of foreign currencies and gold for the period from June 7 to July 4 would amount to the equivalent of 71.1 billion roubles ($801.04 million), or 3.7 billion roubles per day.

Due to other interventions the central bank is carrying out until the end of June, the Russian state will continue making FX sales throughout the month, increasing those to 8.1 billion roubles a day until the end of June.

In the previous period, between May 8 and June 6, the ministry had planned to buy foreign currency worth 110.9 billion roubles, or 5.6 billion roubles per day.

Under its budget rule, Russia sells foreign currency from its National Wealth Fund (NWF) to make up for any shortfall in revenue from oil and gas exports, or makes purchases in the event of a surplus.

Proceeds from oil and gas sales for Russia's federal budget dropped by 35% month on month to 793.7 billion roubles in May, finance ministry data showed. The ministry expects additional oil and gas revenues of 140.7 billion roubles this month.

The central bank, which conducts FX interventions on the finance ministry's behalf, deferred foreign currency purchases last August to avoid aggravating pressure on the rouble, which tumbled past 100 to the dollar in August and October.

This year, the central bank's mirroring of finance ministry operations, including deferred foreign currency purchases from August to December 2023, is being adjusted by the volume of NWF funds spent on financing the government's budget deficit for 2023 and on supporting companies.

The central bank is making daily sales of 11.8 billion roubles until June 28. It has yet to announce an interventions plan for July onwards.

The finance ministry was selling Chinese yuan for the first half of 2023 as Western sanctions imposed over Russia's actions in Ukraine hit energy revenues. It reverted to purchases in August as commodity prices rose and energy revenues recovered.

($1 = 88.7600 roubles) (Reporting by Darya Korsunskaya and Alexander Marrow; Editing by Mark Trevelyan and Hugh Lawson)