Canada's Liberal Party has decisively won parliamentary elections, ending nine years of Conservative rule, partial results show.

The Liberals, led by Justin Trudeau, are leading in 189 electoral districts.

The son of late Prime Minister Pierre Trudeau is now poised to form a majority government, Canada's CBC and CTV networks predict.

Incumbent Conservative PM Stephen Harper - whose party is leading in 102 districts - accepted defeat.

Speaking after the polls closed, he said he had already congratulated  Trudeau, saying the Conservatives would accept the results "without hesitation".

His party said  Harper would resign as leader of the Conservatives.

Meanwhile, the left-leaning New Democratic Party (NDP) looks set to lose a third of the 54 seats it held in the last parliament, according to CBC.

"I congratulated  Trudeau on his exceptional achievement," said NDP leader Tom Mulcair.

To form a majority government, a party needs 170 seats in the 338-member parliament.

Voting hours were staggered across the country and polls opened in Newfoundland at 08:30 local time (11:00 GMT). Polls closed in the west of the country at 19:00 (02:00 GMT).

It was one of the longest and possibly closest election campaigns in Canada's history, with leaders criss-crossing the country to try to sway undecided voters.

Early counts in the eastern provinces gave the Liberals their first taste of victory, as they led in all 32 races there.

As the results began pouring in, former Conservative Justice Minister Peter MacKay said: "A sea of change here. We are used to high tides in Atlantic Canada. This is not what we hoped for."

The Conservatives are now in danger of losing all 13 seats they held in Atlantic Canada in 2011.

In a remarkable turnaround, the Liberals - who held only 36 seats before the election - are now expected to form a majority cabinet.

Analysis: BBC's Anthony Zurcher, Liberal HQ in Montreal

It has become a night of superlatives for the Liberals in Canada.

For only the second time in history, a party has gone from third place in parliament to first.

The Liberals control more seats in Quebec than they've had in a generation, dealing a crushing blow to the formerly ascendant left-leaning New Democratic Party.

They won at least one race in the Conservative fortress of Calgary, hometown of Prime Minister Stephen Harper, for the first time since 1968.

Justin Trudeau campaigned as a candidate of change, and his party is poised to hand the incumbent Conservatives one of the worst defeats in their history.

At Liberal Party headquarters in Montreal, the mood has gone from excitement to pure jubilation, as the crowd cheers win after improbable win.

"I'm so excited," said Karyn Decore, who flew in from Edmonton - another conservative Alberta city that could send a Liberal to parliament - for Monday night's party.

"I could feel in my heart that change was coming. This is history in the making."

 Trudeau, 43, started the race in third place but the Liberals took the lead in opinion polls in a late surge.

He has campaigned on a promise of change, urging voters ahead of the polling day to "come together as a country".

 Trudeau's father, Pierre, is considered the father of modern Canada.

 Harper, 56, portrayed himself as the steady hand who could steer Canada's troubled economy back on track.

His campaign ran TV advertisements saying that  Trudeau was "just not ready" to take office.

"Every single vote for a Conservative candidate is a vote to protect our economy against Liberal and NDP deficits and taxes,"  Harper told supporters in Regina, Saskatchewan, on Sunday.

As polls opened, he tweeted that a vote for the Conservatives would “protect Canadian jobs and our economy”.