* No initial IAEA comment on report of Amano trip to Tehran
* Would be his first since unsuccessful talks in May 2012
* Hints at progress in probe into alleged atomic bomb work
By Yeganeh Torbati and Fredrik Dahl
LONDON/VIENNA, Nov 5 (Reuters) - U.N. nuclear agency chief Yukiya Amano is expected to visit Tehran on Nov. 11, Iranian state television said on Tuesday, a possible sign of progress in a long-stalled investigation into suspected nuclear arms research by Tehran.
After years of worsening confrontation with the West, Iran has switched to a conciliatory mode - entailing diplomacy in search of a peaceful solution to its disputed nuclear activity - since the June election of moderate President Hassan Rouhani.
The International Atomic Energy Agency and Iran have held a series of fruitless meetings since early 2012 to agree ground rules for the IAEA's inquiry, but hopes for a breakthrough have been lifted by Rouhani's rise.
The Islamic Republic denies seeking nuclear weapons, saying it wants only civilian atomic energy.
Ali Akbar Salehi, the head of Iran's atomic energy organisation, said he hoped the two sides would reach an agreement during Amano's visit, state television said on its web site, without giving details.
There was no immediate comment from the IAEA, which wants access to sites, officials and documents in Iran, including the Parchin military base where it believes nuclear-related explosives tests might have taken place, possibly a decade ago.
The IAEA's discussions with Iran are separate from broader negotiations between Tehran and six world powers that resumed in Geneva last month and will continue there on Nov. 7 and 8.
But both diplomatic tracks centre on suspicions that Iran may be seeking the capability to make nuclear weapons.
If Amano's trip is confirmed, it would be his first visit to the Iranian capital since May 2012. That time, he returned saying he expected to sign a deal with Iran soon to unblock the agency's investigation, only to see it fail to materialize.
Rouhani has improved the diplomatic atmosphere since then, however, promising to try to resolve a decade-old international stalemate over Iran's nuclear programme and secure an easing of sanctions severely damaging its oil-dependent economy.
Iran says it is refining uranium only to fuel future nuclear power plants and an existing medical research reactor. But its refusal so far to curb sensitive nuclear work and lack of transparency with the IAEA have drawn harsh sanctions.
After talks last week between senior IAEA and Iranian officials in Vienna, described by both sides as "very productive", a new round was set for Nov. 11 in Tehran, but without any word on Amano possibly taking part.
Salehi said he had invited Amano to visit on that day and that the IAEA director-general had expressed his "inclination" to do so, state television said.
Salehi said he hoped that "we will reach an agreement in this trip" with the head of the Vienna-based U.N. agency and "issue a joint statement".
"The International Atomic Energy Agency has moved forward with a positive approach and as before we will continue to collaborate in a transparent manner and we are more than ever ready to cooperate with the agency," Salehi told reporters on Tuesday, according to the state news agency IRNA.
Iran said in last week's meeting in Vienna, where the IAEA is based, that it had put forward new proposals to the U.N. agency. A diplomatic source described the Iranian ideas as "potential confidence-building" measures but did not elaborate.
Western experts say that Iran will probably only agree to fully cooperate with the IAEA's investigation as part of a broader settlement with the United States, France, Russia, China, Britain and Germany that wins it sanctions relief.