By Ben Klayman

CHICAGO (Reuters) - While the average Major League Baseball team is worth more than a year ago, a third of the U.S. sports league's 30 teams saw their values fall or remain unchanged, according to an annual survey by Forbes magazine.

Overall team values increased an average of 2 percent over the past year to $491 million, according to the survey, released late on Wednesday. Last year, the average team value rose 1 percent.

The most valuable team for the 13th straight year was the New York Yankees, who are worth $1.6 billion, nearly twice as much as their rival Boston Red Sox, the second most-valuable team.

Despite a decline in 2009 attendance, teams also posted a record-high operating income at an average of $17.4 million per team, helped by two new parks in New York, the escalating value of national TV deals and only the second decline in total player costs since 1995, Forbes said.

However, Forbes said nine teams saw their values decline and two others were flat as the recession hurt several markets. The teams with the biggest declines were the Toronto Blue Jays and Oakland Athletics, each down 8 percent.

Baseball, like most U.S. sports leagues, has been hurt by the weak economy that led consumers and companies to curtail spending. League attendance fell 6.6 percent last year to 73.4 million, but revenue rose 1.5 percent to $6.7 billion as the league benefited from higher TV rights.

Baseball officials have said they expect league attendance this season will be flat to up, with a slight increase in overall revenue. However, with unemployment expected to hover around the current rate of 9.7 percent for some time, analysts think that outlook may be optimistic.

Meanwhile, the average ticket price for a baseball game this season rose 1.5 percent to $26.74, but the cost to take a family of four to a game dropped slightly to $195.08 as more teams offer cheaper concession items, according to consulting firm Team Marketing Report (TMR).

Teams seem to be sensitive to the weak economy's impact as TMR reported 18 either cut ticket prices or kept them unchanged. The San Diego Padres (15.4 percent) and Detroit Tigers (14.2 percent) showed the biggest declines, while the Minnesota Twins, playing in a new park, saw prices surge 45 percent.

The Chicago Cubs edged out the Red Sox for the priciest average ticket, $52.56 to $52.32, while the Arizona Diamondbacks sported the lowest price at $14.31, TMR said.

On this year's Forbes list, teams with double-digit increases in value included the Florida Marlins (15 percent), Twins (14 percent) and the Texas Rangers (11 percent).

The Yankees' value rose 7 percent to $1.6 billion and the value of the Red Sox rose 4 percent to $870 million, the magazine said. Rounding out the top five were the New York Mets (down 6 percent to $858 million), the Los Angeles Dodgers (up 1 percent to $727 million) and the Cubs (up 4 percent to $726 million), which the Ricketts family bought last fall from the Tribune Co for $845 million.

The least valuable team was the Pittsburgh Pirates (unchanged at $289 million), according to Forbes.

(Reporting by Ben Klayman, editing by Matthew Lewis)