* Agreement backed by majority of Oleo e Gas's bondholders
* Deal could pave way for successful bankruptcy restructuring
* Accord may release Batista from $1 bln put-option pledge
(Adds agreement details and context)
RIO DE JANEIRO, Dec 24 (Reuters) - Brazilian tycoon Eike Batista's Oleo e Gas Participacoes SA, formerly known as OGX, said on Tuesday it reached a deal with the majority of holders of bonds worth $3.8 billion, a breakthrough that could open the door for a successful restructuring of the bankrupt oil company.
Under the deal, bondholders will be able to take part in a loan of between $200 million and $215 million to keep the Rio de Janeiro-based company operating, according to a company statement.
Bondholders have also agreed in principle to release controlling-shareholder Batista from his commitment to put as much as $1 billion of new investment into the company.
The loan, known as debtor-in-possession, or DIP, finance would be convertible into stock representing 65 percent of a restructured Oleo e Gas.
The deal with bondholders is part of a so-called "plan support agreement" or PSA. Batista and other controlling shareholders of Oleo e Gas and its sister company OSX Brasil SA have also agreed to the plan. Bondholders, though, will withhold approval of the agreement if OSX does not reach a deal with its own bondholders that they support it, the statement said.
Oleo e Gas's 11.2-billion-real ($4.75 billion) bankruptcy filling on Oct. 30 was the largest ever in Latin America and the biggest emerging-market bond default in the last 12 months. A deal with bondholders is needed before the company can convince a judge that any restructuring effort will succeed.
The company said that under the plan the final proposal for judicial restructuring has to be accepted by all parties by Jan. 24.
Bondholders are not obligated to take part in the loan, but those who do will go to the top of the list of creditors to be repaid if a restructuring agreement is accepted.
The DIP loan will be disbursed in two tranches. Creditors who are not bondholders will be allowed to participate in the second tranche of the loan on a "pro rata" basis, the company said.
Those who participated in the first part of the loan will be required to participate in the second one.
The agreement is dependent on Oleo e Gas obtaining bridge loans of between $10 million and $50 million that must be repaid by Jan. 31.
If the deal is implemented in full, $5.8 billion in other company liabilities including money owed to OSX will be converted to shares, the company said.
After the conversion of the DIP loan into stock, other Oleo e Gas creditors will receive 25 percent of the stock in a restructured company.
After the swap of the DIP loan and other credits into stock existing shareholders will be left with 10 percent of the restructured company.
Existing shareholders will be given the right to purchase up to $1.5 billion of new stock in the restructured company for five years, but those rights are not to exceed 15 percent of the restructured company.
The agreement also sets Oleo e Gas's liabilities with OSX at $1.5 billion, the statement said.
Last week, OSX said it expected a deal in the coming days to delay an interest payment on bonds sold to finance the OSX-3, an oil production ship.
The OSX-3 began producing oil and gas from Oleo e Gas's Tubarao Martelo offshore field east of Rio de Janeiro in early December. Tubarao Martelo is Oleo e Gas's only significant source of revenue.
Oleo e Gas's failure to produce as much oil as expected at its first offshore oilfield, Tubarao Azul, led to the meltdown of EBX and nearly wiped out Batista's fortune. That undermined his ability to finance other companies in his group with capital as they tried to transform from start-ups to revenue producing concerns.
OSX, also controlled by Batista, sought court protection from creditors in November in the wake of Oleo e Gas's filing.
(Reporting by Jeb Blount and Alonso Soto; Editing by Gary Hill and Ken Wills)