SAN DIEGO (CNS) - City of San Diego officials will make a pitch Tuesday to Port of San Diego commissioners to chip in $3 million annually to help pay for the proposed expansion of the San Diego Convention Center.

The contribution over a 20-year period would be part of a financial package that also includes a surcharge on hotel room rates.

Supporters of expansion believe a bigger convention center will be able to book larger meetings currently going to other cities, and the financial benefits will spill over to area hotels and restaurants. They also think the port's tenants, which range from waterfront hotels to sports fishing enterprises, will benefit. The center sits on port property but is operated by the city.

City spokesman Darren Pudgil said a contribution from the port is factored into the financing plan for the $550 million expansion project.

"It's an important part of the equation and we're hoping the port will see the benefit (of expansion) to the region and their tenants," Pudgil said.

A consultant's report projects the port will earn an additional $6 million in revenues if both the convention center and nearby Hilton San Diego Bayfront Hotel are expanded. The hotel plans to add 500 rooms in a separate project.

Port staff recommends that they continue to negotiate with city counterparts and return at a later board meeting with a definitive agreement.

Earlier Tuesday, the Chula Vista City Council will hold a special meeting in which they will consider a resolution that expresses support for the expansion but calls on the port to make no financial commitments until the project is approved. Chula Vista is a Port District member along with other cities that have shoreline along San Diego Bay.

City and convention officials say 111 conference organizers have bypassed San Diego as a destination in recent years, despite being interested in coming, because other towns offer more space. The show with the biggest impact on San Diego, Comic-Con International, was nearly moved to Anaheim or Los Angeles because of space limitations.

The project would increase the size of the building by 961,187 square feet, to more than 2.75 million square feet. The floor space of meeting rooms and ballrooms would double under the plan.

Having more room could attract an extra 25 major annual events to the center, worth $121 million annually in additional hotel room night income, according to a consultant's study.