MOSCOW -(Dow Jones)- Russian drug group OAO Protek Tuesday said it plans to hold an initial public offering for $400 million toward the end of May, with around half of that sum going to existing shareholders.

Protek has received permission from Russian regulators to list 117.5 million shares, representing a fifth of its post-issue capital, which would imply a valuation of $2 billion for the group.

"The shares will be placed at the end of May or the start of June...on the two Russian exchanges," Chief Executive Vadim Muzayev told journalists on a conference call.

He declined to say how much the company might be worth, adding the company will receive around half of the cash to invest in product development and expansion.

The company had revenue of 91.58 billion rubles ($3.01 billion) in 2008, with earnings before interest, depreciation and amortization of RUB5.84 billion.

Muzayev said the Russia's pharmaceutical market is likely to grow between 10% and 12% this year from 2009.

Protek is Russia's largest distributor of pills and medicine--accounting for just over a fifth of that market.

The offering is being organized by UBS Investment Bank and Moscow-based Renaissance Capital.