Capital plan may give Petrobras $25 bln oil rights

* Analysts see capitalization at $15 bln-$25 bln

* Gov't plan would give Petrobras 5 bln bbl in reserves

* Average estimate of $3 to $5 per bbl of reserves

By Denise Luna

RIO DE JANEIRO, Sept 15 (Reuters) - Brazil's plan to
capitalize state-run oil company Petrobras with 5 billion
barrels of crude reserves in exchange for new shares may yield
$15 billion to $25 billion in oil rights for the company,
analysts said on Tuesday.

President Luiz Inacio Lula da Silva last month gave
Congress a proposal for the capitalization, which is meant to
strengthen Petrobras' (PETR4.SA) (PBR.N) balance sheet as it
ramps up exploration of the vast offshore subsalt fields.

Four analysts polled by Reuters said the final agreement
between the government and the company will probably assign a
value of $3 to $5 per barrel for the offshore reserves, far
below the $10 figure initially floated by government leaders.

The move would give Petrobras additional reserves on its
books to facilitate financing for new subsalt projects. Lula's
proposed laws would make Petrobras the sole operator of future
projects in the subsalt province.

Critics say the proposal involves an unnecessarily complex
securitization of unexplored fields and risks diluting minority
shareholders -- who will have to add additional capital as well
to keep their current stakes.

"It is a very good proposal for Petrobras, but is risky for
minority shareholders," said Nelson Matos of Banco do Brasil
Investimentos. He put the reserves' value at $3.80 to $5 per
barrel based on factors such as the crude's expected quality.

Brazil's Geracao Futuro estimated the value of the oil at
$5 per barrel, while Brazil's Banco Fator estimated the value
at $3 per barrel. Credit Suisse put the value of the oil at $5
to $6.5 per barrel.

Congressional leaders last month gave a preliminary value
estimate for the reserves of $10 per barrel.

The first step is for Congress to approve the proposal.

The government would then have to delineate the area that
holds the reserves, hire an independent certifier to provide a
volume estimate, and receive necessary approval from the
securities regulator.

Opposition leaders have also promised to challenge the
proposal in the courts.

The government holds 32.2 percent of the company's total
market capitalization and 55.6 percent of voting shares.

The total amount Petrobras receives from the operation will
also include the amount minority shareholders put in to match
the government's capitalization and maintain their percentage
stake in the company.

Credit Suisse said Petrobras could receive an additional
$17 billion from contributions by minority shareholders.

The proposal is part of a package of laws that would create
a new state company to administer subsalt contracts, switch
from a concession system to a production sharing system and
open a fund to invest oil revenues in health and education.
(Writing by Brian Ellsworth, editing by Matthew Lewis)