The fourth game, in which the New York Yankees shut out the San Diego Padres 3-0 in San Diego to cap a four-game sweep of the series, measured only a 16.6 rating and a 27 per cent share of the market, bringing the four-game average to a 14.2 rating and a 24 share.
One rating point translates into about 994,000 viewers, or around one per cent of households in the United States with televisions. The share figure represents the percentage of those viewers watching TV who were tuned into the game.
The previous World Series low was an average 16.4 rating and a 27 share for the 1989 series between the Oakland Athletics and San Francisco Giants that also lasted only four games of the best-of-seven championship.
Normally, for a championship series, a television network budget envisages losing money through the first four games, breaking even in the fifth, with the sixth and seventh being pure profit, industry sources said.
In the case of Fox's World Series broadcasts, the network was bringing in about $16m (pounds 9.4m) a game, meaning its loss for the series was probably just about the same amount since the series never reached the fifth game.
A Fox Sports spokesman, Vince Wladika, declined to comment on the profitability of the Series, but he disputed one news report which had claimed that Fox had paid $115m for the championship games. He said Fox's contract with Major League Baseball called for $565m spread over five years of regular season coverage and three World Series.