WASHINGTON — President Barack Obama's re-election campaign has run more than 500,000 television commercials since the start of the general election in April, outstripping Republican challenger Mitt Romney on the air by a margin of 2.6 to 1, according to the latest study by the Wesleyan Media Project.

WASHINGTON — President Barack Obama's re-election campaign has run more than 500,000 television commercials since the start of the general election in April, outstripping Republican challenger Mitt Romney on the air by a margin of 2.6 to 1, according to the latest study by the Wesleyan Media Project.

Through Oct. 29, Obama and the Democratic National Committee spent a record $281.1 million on broadcast and national cable ads, according to the Wesleyan project, which analyzes data from the ad tracking firm Kantar Media/CMAG.

Romney and the Republican National Committee spent $150.6 million between April 11 and Oct. 29.

That's not even the total spending: The firm does not track spots on local cable networks, which likely have aired at least 20 percent of the ads run on broadcast television.

While Obama has enjoyed a consistent advantage on the airwaves, conservative "super PACs" and other outside groups sponsored more than half of the pro-Romney commercials, helping the Republican candidate nearly make up the gap.

When all outside efforts are included, pro-Obama ads outnumbered pro-Romney ads by fewer than 50,000 spots.

In all, nearly 1.1 million presidential campaign ads have aired this year — including 400,000 just in October.

That translates to 39 percent more spots than were run in 2008.