TMK said the placement would strengthen its position on equity capital markets by bringing in new investors, raising the number of its free-float shares and increasing liquidity.

"In addition, increasing free-float will be a step on the road to TMK shares being included in the calculation base for a series of Moscow Exchange indexes," TMK said in a statement.

TMK Steel Holding, which owns 90.6% of TMK's shares, will offer shares equating to around 1.5% of TMK's total shares in the SPO, TMK said. The final offer price will be set no later than Sept. 29.

Investors who participate in the SPO will be entitled to purchase one additional share at the SPO price six months after the offer's completion, TMK said.

Cash raised by the company will be used to reduce debt and for other corporate purposes, TMK said.

($1 = 96.4175 roubles)

(Reporting by Anastasia Lyrchikova Writing by Alexander Marrow Editing by Jason Neely and Mark Potter)