* Batista to sell at least 5 pct more of his OGX stake
* Batista to retain at least 50.01 pct of OGX
* Magazine report of Batista-BTG breakup further pressures stocks
By Jeb Blount
RIO DE JANEIRO, Aug 29 (Reuters) - Brazilian tycoon Eike Batista, the controlling shareholder of OGX Petróleo e Gás Participações SA, sold 1.54 percent of the oil company's stock to pay debts of his EBX group, OGX said in a securities filing on Thursday.
Batista made the sale on Wednesday, OGX said, bringing his total sale of stock in OGX to 5.67 percent since March. Batista plans to sell at least another 5 percent of his OGX stake, but plans to maintain his controlling interest of at least 50.01 percent of OGX shares, according to a securities filing.
OGX, whose shares fell as much as 21 percent on Thursday, has led a year-long the meltdown of Batista's EBX Group which includes energy, shipbuilding, mining and port operations. The group, once worth more than $60 billion, has seen its value nearly evaporate in the last year-and-a-half.
Lower than expected oil output at OGX raised concerns about the group's abilities to generate cash flow to fund expansion and pay debt, creating a crisis of confidence in other EBX companies, many of which depended on each other for revenue.
The OGX slide has led to a wider restructuring of the EBX empire, with Batista agreeing to give up control of port operator LLX Logística SA and electricity generator MPX Energia SA to foreign companies in exchange for new investment.
While he has maintained most of his holdings, Batista has made small sales in recent months to pay debts.
Batista has been using Brazilian investment bank Grupo BTG Pactual SA to help him reorganize his companies and finances. The accord, signed in March, has provided Batista and EBX with access to loans, advice and other services.
Shares of OGX and other EBX companies came under additional pressure on Thursday after the Veja weekly news magazine said BTG Pactual and Batista will end their relationship. Veja did not name any source in its report.
BTG Pactual's returns on the partnership depend on the performance of EBX Group stock. EBX Group stock has fallen sharply since the accord was made in March. BTG Pactual and the EBX Group declined to comment on the news report.
The sale of OGX stock is the second asset sale announced by Batista's EBX this week. On Tuesday, OSX Brasil SA, EBX's shipbuilding unit, said Batista would sell $50 million of stock in the shipyard to help pay for a promised capital injection into the company.
Batista's Centennial Asset Mining Fund LLC and Centennial Asset Brazilian Equity Fund LLX, companies that form the basis of the EBX Group's holdings, held 58.92 percent of OGX as of July 10, according to Thomson Reuters data.
OGX stock fell 12.3 percent on Thursday to close at 0.49 reais, its lowest close in six weeks.