MOSCOW, April 23 (RIA Novosti) - Severstal, Russia's top steel producer, announced Wednesday that it had completed the purchase of outstanding management shares in U.S.-based SeverCorr, which will see Severstal up its stake in the U.S. firm to 85%.

And in a news release the company announced the appointment of Mark Miller as vice-president and project director with Tom Marchak as vice-president of sales and marketing.

Severstal also said it would make other internal appointments to the executive management to ensure continuity, as the current management team plans to leave the U.S. steel maker. In January, James Hrusovsky was appointed CEO to assist with the new team's transition.

Severstal's U.S.-based companies account for 16% of company earnings, clear evidence that the U.S. market is of paramount importance for Severstal.

SeverCorr currently produces 1.3 million tons of high-quality rolled steel per year with 1.5 million tons at full capacity, which is expected to double in 2011.

The company employs 450 workers and makes products for car manufacturers, as well as the construction, pipe-making and machine-building industries.

Severstal is a leading international steel producer by profitability and combines the growth potential of Russia's emerging market with the margin sustainability of an international steel producer.

Severstal produced 17.5 million tons of steel and raised $15.2 billion in earnings in 2007. Earnings before interest, taxes, depreciation and amortization (EBITDA) stood at $3.7 billion.