* Companies in EBX conglomerate tumble on market dive
* Batista's EBX stake falls by $1.9 billion
* OGX investors lose nearly half of money raised in IPO
By Brian Ellsworth and Jeb Blount
RIO DE JANEIRO, Aug 4 (Reuters) - Brazil's Eike Batista may no longer be the world's eighth-richest man after losing some $2 billion on Thursday in a market rout that saw his companies lead losses on Latin America's largest stock exchange.
The flamboyant billionaire's more than two-thirds stake in the EBX group -- an oil, gas, mining and transportation conglomerate with a market capitalization of $31 billion but almost no revenue -- lose about 9 percent of its value.
The Rio de Janeiro-based entrepreneur's share is now worth about $19.2 billion.
His flagship iron-ore mining firm MMX Minerais e Metalicos (MMXM3.SA) led losses on Brazil's benchmark Bovespa markets/index?symbol=br%21ibov">.BVSP index with a drop of 16 percent, slicing 725 million reais off its market capitalization. Batista owns 32.2 percent of the mining company.
Oil and gas firm OGX Petroleo e Gas (OGXP3.SA), fell 8.33 percent, a decline that trimmed its value by 3.23 billion reais, nearly half of the 6.7 billion reais Batista raised in OGX's 2008 initial public offering. He owns 61.2 percent of the firm.
OGX, slated to begin producing crude in October, is Brazil's second-largest oil company by market capitalization and estimated reserves. The losses outpaced the index, which closed down 5.7 percent.
The EBX conglomerate of five listed companies was especially vulnerable to the sell-off because it has large numbers of foreign investors who exited emerging markets in droves on Thursday, said Lucas Brendler, an analyst with Geracao Futuro.
"Companies that are in a pre-development phase are also the ones that end up being hit the hardest in these situations," Brendler said. He added that such firms would likely be able to bounce back faster than larger companies if markets start to recover.
Critics have frequently questioned the high valuations of his company's stock prices. OGX, which has not yet produced any oil, has at times had a market cap rivaling that of Spain's Repsol (REP.MC) -- an integrated oil company with operations around the world.
OGX says it expects to produce 1.4 million barrels of oil and gas equivalent a day from fields in Brazil by 2019.
Shareholders that lost money with Batista include Chinese steelmaker Wisco (600005.SS), Korean commodities group SK, New York-based BlackRock (BLK.N), the world's largest money manger by assets and the Toronto-based Ontario Teachers Pension Plan.
An EBX spokesman did not immediately respond to requests for comment on the share price decline.
Batista, a former speedboat racer who is Brazil's richest man, adds "X" to the names of his companies to symbolize multiplication of wealth. He was listed in 2011 by Forbes' magazine as the world's eighth-richest person with a fortune of $30 billion.
Logistics firm LLX (LLXL3.SA), which is developing two large port projects in Rio de Janeiro state, fell 13.2 percent, slicing 367 million reais off its market value.
Shipbuilding startup OSX (OSXB3.SA) fell 10.9 percent, or 426 million reais, while power generation firm MPX (MPXE3.SA) dropped 8.0 percent, a decline that cost investors 403 million reais.
Batista got his start in Brazil's informal, wildcat gold mines during the 1980s. Over the following two decades become known for his business instincts and capacity for quickly making large profits for his investors as well as controversy. His Canadian based TVX gold became embroiled in several lawsuits and lost some of its initial gains for investors.
He has presented OGX and MMX as alternatives to Brazilian state-run oil firm Petrobras (PETR4.SA) and mining giant Vale (VALE5.SA), both of which have lost billions of dollars in value this year on investor concerns about heavy government intervention.
His backers, which include heavyweight investors from powerhouses like China and Korea, say his companies show enormous promise due to huge reserves of natural resources and capacity for synergies between different EBX subsidiaries.
(Additional reporting by Brad Haynes; Editing by Lisa Shumaker)