Russia's federal budget revenues in 2014-2016 will rely more heavily on oil exports, according to a law signed by President Vladimir Putin on Monday.

The law, "About amendments to the federal budget on 2014-2016", envisages a budget surplus of 0.4 percent of gross domestic product (GDP) in 2014, while an earlier forecast supposed the budget would suffer a 0.5-percent deficit.

Oil revenues' contribution to the surplus has increased to 10.5 percent of the GDP, while non-oil revenues has fallen to 9.6 percent, according to the law, which was passed by the Parliament on June 25.

Non-oil-based budget deficit is to grow to 10.1 percent of the GDP, compared with the previous forecast of 9.4 percent.

Government spending will remain unchanged at 19.5 percent of the GDP.

"The GDP growth in January-May amounted to 1.1 percent year-on-year, with April's growth reaching 1.3 percent as oil and gas export volume increased," according to the economic report of January-May 2014 published by the Russian Economic Development Ministry.