Brazil's Petrobras sees few prospects for Iran oil

* Petrobras sees limited prospects in Iran

* Focusing on developing domestic sub-salt reserves

* Will continue projects in U.S., Turkey

By Brian Ellsworth and Denise Luna

RIO DE JANEIRO, July 3 (Reuters) - Brazil's state oil company Petrobras expects exploration of an Iranian block will yield disappointing results, a company director said on Friday, adding another Iranian block has shown similarly dim prospects.

Petrobras (PETR4.SA: Quote, Profile, Research)(PBR.N: Quote, Profile, Research) International Director Jorge Zelada said in an interview that the offshore Tusan block in the Gulf that the company won rights to in a 2003 bidding round was geologically unappealing.

"Our expectation is for a sub-commercial reserve," said Zelada. "It is a small reserve ... we have not yet finished the report, but the expectation is that it does not have commercial possibilities."

Petrobras invested around $100 million to drill two wells in Tusan and in February said it had found signs of oil.

The company had also been evaluating data from a block in the Caspian Sea, but decided against an exploration campaign because the block appeared to hold mostly natural gas, rather than oil, in an area that did not have infrastructure for gas production.