* First output will come from Amazon fields this year
* Will also drill in Namibia by late 2012, early 2013
* Set to sell stakes in Namibia blocks this year
* HRT expects 28 bln barrels oil, gas in Namibia blocks
RIO DE JANEIRO, May 11 (Reuters) - Shares of HRT Participações em Petróleo SA rose more than 5 percent in São Paulo on Friday after company officials said they expect the Brazilian oil company to have its first commercial output this year and that it could have as much as 28 billion barrels of oil and gas in Namibia.
The Rio de Janeiro-based start-up's first output is expected from HRT's Amazon oil and gas prospects in Brazil's Solimões basin, Chief Financial Officer Lourenço Bastos-Tigre said on a conference call with investors Friday.
HRT sold 45 percent of 21 Amazon oil blocks to Anglo-Russian TNK-BP, Russia's third-largest oil producer for $1 billion in October. TNK-BP is half-owned by BP Plc., the British oil group.
HRT's resources in Namibia, while not completely certified or audited, are undergoing an independent review by Dallas-based oil consultant DeGolyer and MacNaughton, said Wagner Peres, chief executive of HRT Americas, the HRT unit that controls the Namibia operations.
After the review, the Namibia estimate is likely "to be the same or larger" than HRT's "unrisked" projection of 28 billion barrels of oil and gas equivalent in seven Namibian prospects, an HRT official said on the call. Resources in three of the prospects are already certified and four are in the process of certification.
At 12:40 p.m. (1540 GMT) HRT shares rose 4.5 percent to 476.04 reais ($240), their first gain in four days and their biggest gain in two weeks. Earlier they rose as much as 5.2 percent to 484 reais.
HRT plans to start drilling in Namibia in late 2012 or early 2013, the company said. It also expects to sell stakes in some of its Namibian blocks this year, and has spoken with 10 potential investors about its so-called farm-out plan, Peres said.
Efforts to develop its Amazon oil and gas resources were hampered in recent weeks by high water on a stretch of the Amazon River known as the Rio Solimões. This could potentially delay the company's drilling activities in the region.
The high water underscores the difficulties of working in the remote Amazon region. While the company should be able to move oil relatively easily by tanker on the region's waterways, natural gas presents other problems.
To avoid having to build long, technically challenging and expensive pipelines to the Amazon's isolated cities, HRT is in talks with utilities and manufacturers t o sell them gas to produce electricity or make petrochemicals, it said.
This could make it easier for HRT to sell its resources that could otherwise be "trapped" in reservoirs far from market.