The San Diego Unified Port District gave conditional approval to a plan under which the port would contribute $60 million — up to $3 million a year for 20 years — to help fund the proposed $550 million expansion of the San Diego Convention Center.

Port commissioners voted unanimously Nov. 29 to have port staff begin negotiations with the City of San Diego on terms of support agreements. The action followed a Nov. 8 request from San Diego Mayor Jerry Sanders, whose office proposed the port district contribution.

Studies by port consultants estimate the district could garner new annual revenue ranging from $3.5 million to $6.2 million a year, depending on whether the convention center expansion and a proposed 500-room expansion of the next-door Hilton San Diego Bayfront Hotel are developed at the same time.

Port Commissioner Dan Malcolm called for additional studies that would include a “worst-case scenario,” to address the impact if the convention center expansion or hotel plan doesn’t generate the expected financial benefits. Port officials also want to ensure that the investment does not adversely impact long-term commitments to other port cities.

In October, San Diego City Council approved a measure allowing for the creation of a Convention Center Facilities District, subject to approval by a two-thirds majority of local hotels, which would finance the bulk of the expansion’s cost through tax collections.

At the latest port meeting, Sanders said the port district would share in a projected $698 million in economic benefit to the region from an expanded convention center.

— Lou Hirsh