A new plume of black smoke over the Sistine Chapel today indicated that Catholic cardinals had failed, after three rounds of voting, to elect a new leader for their 1.2 billion-strong Church.
The 115 cardinals had gone into seclusion yesterday to find a successor to Benedict XVI, who brought a troubled eight-year papacy to an abrupt end by resigning last month aged 85.
The black smoke -- a signal given not after each failed vote but after every two such rounds -- indicated that no one had gained the two-thirds majority needed to become the 266th pope.
A successful result would be signalled immediately by white smoke and followed soon afterward with the famous announcement in Latin, "Habemus Papam" (We Have a Pope).
The failed balloting deepened the suspense as no clear frontrunner has emerged, although conjecture has coalesced around three favourites: Italy's Angelo Scola, Brazil's Odilo Scherer and Canada's Marc Ouellet, all conservatives like Benedict.
"So far there is no majority, but some candidates with little support will fall by the wayside soon," an anonymous cardinal who is too old to vote in this conclave but took part in preliminary meetings told the Italian daily La Stampa.
Some analysts suggest that Benedict's dramatic act -- the first papal resignation in over 700 years -- could push the cardinals to take an equally unusual decision and that an outsider could emerge as a compromise candidate.
Hopes are high in the Philippines for the popular archbishop of Manila, Luis Antonio Tagle, and on the African continent for South Africa's Wilfrid Napier, the archbishop of Durban, but in practice their chances are slim.
Two-thirds of the cardinals are from Europe and North America, and the view among many experts is that only someone with experience of its inner workings can reform the scandal-tainted Vatican bureaucracy, the Roman Curia.