SAN DIEGO -- The City Council agreed Tuesday to formally put San Diego forward as one of the cities where World Cup matches would be played if the United States is selected to host the soccer tournament in 2018 or 2022.

The council voted 6-2 to authorize the mayor's office to sign an agreement with FIFA, soccer's worldwide governing body, that formalizes San Diego's interest in hosting World Cup matches.

Councilwomen Donna Frye and Marti Emerald cast the dissenting votes, saying they were concerned the agreement was not properly vetted by the City Attorney's Office, and that it wasn't clear what obligations San Diego would have as a host city.

"Before I do vote, I really do want to get an analysis of this contract," Emerald said.

The cost of pursuing the host city bid, which was estimated at under $10,000 a year, would be covered by the San Diego Sports Commission, a private organization that promotes local sporting events, according to Alan Kidd, the group's president.

San Diego is one of 27 cities being considered to host World Cup matches if the tournament comes to the United States. The U.S. Bid Committee, a consortium of American soccer organizations and supporters, has been established to try to persuade FIFA that the United States should host the tournament.

The U.S. Bid Committee will narrow the number of cities where World Cup matches would by played to 18 by the end of next month. FIFA is scheduled to announce the host countries for 2018 and 2022 in December 2010.

Mike Connerley, director of the San Diego Surf Cup Soccer Tournament, told the City Council that hosting World Cup matches in San Diego would be a "once-in-a-lifetime opportunity."

"Please help us bring this bid to the city of San Diego and make it a reality," he said.

Council President Ben Hueso said the event would be an economic goldmine and draw tourists to the region from around the world.

"No event gets more exposure than this one," he said.

If San Diego is ultimately selected, it would have to agree to offer the use of a stadium, hold a festival and pay for public safety. The cost for each city hosting World Cup matches is estimated at $12-$15 million.

Right now, the city envisions using Qualcomm Stadium, but that could change if San Diego builds a new stadium.

According to a report to the City Council, holding a World Cup in the United States would generate a $350-$550 million economic benefit for each host city and a $6.4 billion economic impact nationally.

The World Cup, the world's most widely viewed sporting event, is held every four years. It consists of 64 matches played by 32 international teams in more than a dozen cities throughout the host nation.

The last World Cup was held in Germany in 2006. The 2010 World Cup is being held in South Africa. It then goes to Brazil in 2014. The tournament was last played in the United States in 1994.