Sept. 24 (Bloomberg) -- New York Mayor Michael Bloomberg leads Democratic city Comptroller William Thompson by 16 percentage points with less than six weeks until the Nov. 3 mayoral election, a Quinnipiac University poll reported today.

Likely New York City voters favored Bloomberg, an independent seeking a third four-year term on the Republican and Independence Party ballots, over Thompson, 52 percent to 36 percent. Conservative Party candidate Stephen Christopher had 2 percent, with 9 percent undecided.

Hamden, Connecticut-based Quinnipiac said it took its survey from Sept. 15, the day Thompson won the Democratic mayoral primary with about 70 percent of the vote, to Sept. 21 and interviewed 1,513 likely voters with a 2.5 percentage point error margin.

“Comptroller William Thompson, fresh from a big Democratic primary win, got no post-primary bounce in his campaign to unseat Mayor Michael Bloomberg,” Maurice Carroll, director of the Quinnipiac University Polling Institute, said in a news release. “While Thompson is climbing that mountain, Bloomberg is rolling huge rocks in the form of a multimillion-dollar media blitz down on his head.”

Bloomberg, 67, who self-financed his 2005 re-election campaign for $80 million, spent almost $36.7 million on the current race by July, according to the city Campaign Finance Board. Thompson, 56, expects to spend about $12 million, campaign spokesman Mike Murphy said.

The poll found that voters approve of Bloomberg’s performance, 69 percent to 26 percent. Thompson received a 53 percent to 12 percent approval rating, with 35 percent undecided.

“For a citywide official of real importance, his job approval ‘don’t know’ number is high,” Carroll said.

In an Aug. 16 Quinnipiac poll, Bloomberg led Thompson by 15 percentage points and in a survey released July 28, the gap was 10 percentage points.

Likely city voters also said they support a smoking ban in parks and beaches, which city Health Commissioner Thomas Farley proposed earlier this month, 52 percent to 43 percent. While women supported the ban 57 percent to 38 percent, men opposed it 49 percent to 44 percent, the poll found.

The mayor is founder and majority owner of Bloomberg News parent Bloomberg LP.

To contact the reporters on this story: Henry Goldman in New York at hgoldman@bloomberg.net

Last Updated: September 24, 2009 06:30 EDT