After a record-setting season for TV ratings, Nielsen believes that Super Bowl XLV may have been the highest-rated TV program of all-time.

According to the overnight numbers released by Fox, the game tied for the highest-rated National Football League championship game, scoring a 47.9 market share, tying with Super Bowl XXI.

Last year's Super Bowl on CBS broke the record for number of TV viewers previously held by the series finale of the Korean War dramedy M*A*S*H* which aired in 1983. Fox's is forecasting a three percent increase over last year's ratings, which would suggest that 109.7 million U.S. households tuned into the game.

This season, an NFL game was the highest-rated program for each of the league's 17 regular season weeks as well as the playoffs and accounted for 28 of the 30 highest-rated programs.

UPDATE: According to Sports Illistrated's Richard Deitsch, Super Bowl XLV averaged around 111 million U.S. viewers--more than the 109.7 million figure estimated earlier--officially becoming the most-watched program in U.S. television history.