NEW YORK — NBC has sold nearly all of its commercial time during next year’s Super Bowl, beating expectations despite a soft advertising market.

The network said Thursday it has sold 85 percent of its available slots. Strong categories include automobiles and movies.

A dozen 30-second commercials sold for $3 million apiece. With only about 10 slots left, NBC could command even more money for each.

Normally, about 60 percent of Super Bowl ad slots get sold by this time of year, when the professional football season’s final bout is still more than four months away.

The Wall Street Journal reported on the development earlier on its Web site.

Sporting events have been a rare bright spot for media companies facing declining ad revenue this year in the weak economy. Although television ratings have been dropping for years as audiences turn to video recorders and alternative viewing platforms such as computers and Apple Inc.’s iPods, people tend to want to watch big sporting events live and on high-quality screens.

Viewership for NBC, a unit of General Electric Co., was better than expected during the Olympics Games and exceeded the minimums NBC guaranteed advertisers, allowing the network to free up time slots it had reserved to make up for any shortfalls.

NBC said it sold $25 million in ads during the Games, on top of more than $1 billion sold beforehand.