More than 67 million Americans tuned in to Wednesday's first presidential debate between President Barack Obama and Mitt Romney, ranking the match-up among the top 10 of the past 30 years.

Final Nielsen data on Thursday showed that 67.2 million people across 11 TV networks watched Obama and Romney go head to head on the economy - a 28 percent increase on the 52.4 million who saw the first 2008 debate between Obama and Republican John McCain.

Wednesday's audience was also higher than any of the TV debates between the presidential candidates in both the 2004 and 2008 elections.

But Obama and Romney failed the capture the audience riveted by the vice-presidential encounter four years ago between Republican Sarah Palin and Democrat Joe Biden, which was watched by 69.9 million - which ties as second most-viewed debate ever.

According to Nielsen, which only began collecting such debate data in 1976, the most-watched presidential debate on U.S. television was the October 1980 encounter between Ronald Reagan and Jimmy Carter, which drew 80.6 million viewers.

Other high points were recorded by the three-way Bill Clinton, Ross Perot and George H.W. Bush match-up in 1992 (69.9 million), Gerald Ford and Jimmy Carter in 1976 (69.7 million) and Michael Dukakis and Bush in 1988 (67.3 million).

Romney and Obama will debate twice more before the Nov. 6 elections. – Reuters