The San Diego City Council on Dec. 6 approved plans for a special financing district to support a proposed $520 million expansion of the San Diego Convention Center.

The measure passed by a 6-2 vote, with David Alvarez and Sherri Lightner dissenting.

Local hotels, which would finance the bulk of the cost, are expected to vote on the district measure in April. The financing district plan requires the approval of two-thirds of local hotel owners.

Starting in January 2013, hotels in the city would add a fee of 1 to 3 percent to guests’ bills, depending on the properties’ proximity to the Convention Center, with the higher percentage to be assessed by downtown hotels.

San Diego city and Convention Center officials are working out full financing plans for the expansion. Last week, Port of San Diego officials gave conditional approval to a plan that would have the port district contribute up to $60 million to the project — $3 million annually for 20 years.

— Lou Hirsh