VATICAN CITY - Black smoke emerged from the Sistine Chapel chimney again today as the scarlet-robed cardinals inside failed in two more ballots to elect a new pope to build on John Paul II's legacy and heal deep rifts within the Roman Catholic Church.

Several thousand pilgrims and tourists who packed St. Peter's Square to stare at the slender stovepipe jutting from the chapel's brown tiled rooftop gasped when the smoke appeared just before noon. The 115 voting cardinals sequestered in the chapel were to break for lunch and reconvene in the afternoon for the day's final session of secret balloting.

White smoke - and the pealing of bells shortly afterward - eventually will tell the world that the church's 265th pontiff has been chosen to succeed John Paul, who died April 2 at age 84.

The smoke this morning confused onlookers for the second time in two days. But this time bells added to the uncertainty as well.

The crowd was quiet as it tried to determine the color of the smoke, which initially appeared to be gray. As the plume darkened, the pilgrims began to disperse as the chimney stopped spewing the black smoke.

But when the bells of St. Peter's Basilica tolled - as they do every noontime - many still in the square thought it was the signal that a new pope had been elected. Only when the chimney spewed more black smoke was the outcome clear.

Murmurs in several languages - "nero," "black," and "schwartz" - then swept the square.

The two morning ballots today followed an early Mass in the cardinals' high-security Vatican hotel. The prelates from six continents and 52 countries were to return to the chapel this afternoon for up to two afternoon ballots, with a new plume of smoke expected by late evening.

If the afternoon session also fails to produce a pope, the conclave will resume Wednesday morning. On each day of voting, the cardinals hold two ballots each morning and two each afternoon. After the voting sessions, the ballots and any notes are burned.

"All the people here have something in common: the religion, of course, but also being a part of history. This is a part of history," said Adrien Asselin, 66, of Hawkesbury, Ontario, a retired art teacher who cut short a trip to South Africa to fly to Rome.

The first conclave of the new millennium is being held amid unprecedented security, with the cardinals seated atop a false floor concealing electronic jamming devices designed to thwart eavesdroppers by cutting signals to cell phones or bugs.

On Monday evening, black smoke that initially looked light enough to throw even Vatican Radio analysts off-guard poured from the chimney, disappointing a crowd of 40,000 pilgrims anxious for a sign that the cardinals had settled on a successor.

The cardinals have a staggering range of issues to juggle as they choose the first new pope of the 21st century - fallout from priest sex-abuse scandals, chronic shortages of priests and nuns, as well as calls for sharper activism against poverty and easing the ban on condoms to help combat AIDS.

The next pontiff also must maintain the global ministry of John Paul, who took 104 international trips in his more than 26-year papacy.

"Keep praying for the new pope," said 82-year-old Cardinal Luis Aponte Martinez of Puerto Rico, who was too old to join the conclave, open only to cardinals under 80 years old.