VIENNA (Reuters) - U.N. nuclear inspectors and Iran appear to have failed in talks this week to finalize a deal to resume their long-stalled investigation into suspected atom bomb research in the Islamic state, a diplomatic source said on Thursday.

The U.N. International Atomic Energy Agency (IAEA) and Iran were expected to hold a further meeting on February 12, following two days of negotiations in Tehran this week that ended on Thursday, the source added.

(Reporting by Fredrik Dahl; Editing by Mark Heinrich)