MOSCOW, August 17. /TASS/. An initiative to tax windfall incomes from Russian mining and chemical sectors would lead to defaults of certain companies and slow down GDP, the Russian Union of Industrialists and Entrepreneurs warned on Friday.

"Companies will face an overall crisis of creditworthiness and solvency," the Union cautioned. "Implementing the initiative can lead to a default of some companies," it adds. This tax would violate the general principles of business activity, the Union says.

This move would hinder carrying out Russian President Vladimir Putin’s May Decree on boosting exports of non-resource goods, the Russian Union added.

"The suggested initiative will lead to the inability of fulfilling the Russian President’s May Decree in terms of the breakthrough development of branches and the increase in non-resource goods export," the Union says.

Taxing "the most efficient companies of the economy’s systemic branches removes any incentives to improve enterprises’ performance and productivity," it notes.

The idea to withdraw 513.7 bln rubles ($7.7 bln) from the metallurgical and chemical companies from their additional revenues was previously proposed by Andrey Belousov in a letter to Vladimir Putin. According to Belousov, the money can be spent on carrying out the May presidential decree.

The list of companies include NLMK, Severstal, Magnitogorsk Iron and Steel Works, Mechel, Metalloinvest, Evraz, Norilsk Nickel, Alrosa, Polyus, Sibur, Uralkali, Phosagro and others.

According to the estimates of the Russian Union of Industrialists and Entrepreneurs, the capitalization of the Russian stock market may drop by 3 trillion rubles ($45 bln) because of these measures. The organization also warned that Belousov's initiative would negatively affect the country's investment attractiveness.

Taking away additional revenues from metal and chemical companies in Russia may affect their profitability, Fitch rating agency said earlier this week.