PORTLAND — City planners and the public on Tuesday got a fresh glimpse at what a long-awaited $100-plus-million development on one of Portland’s most visible waterfront properties will look like.

Developers behind The Forefront at Thompson’s Point — which will build out the Fore River peninsula with office buildings, restaurants, a hotel, a sports arena, parking garages, condominiums and a sports medicine lab, among other facilities — began pursuit of the city’s “master development plan” status during a Tuesday night Planning Board workshop.

An earlier rendition of the ambitious project won city approval in 2012, but in October, the city flipped to the developers another three acres it acquired from Suburban Propane, pushing the total size of the project to more than 32 acres and giving builders new flexibility to rearrange the campus layout.

As a result, however, the previously approved plans are now out-of-date, and the development group must return to the Planning Board to seek the green light for the latest adjustments.

Chris Thompson of Forefront Partners said his team now also plans to pursue the master development plan designation, which will further cement the city’s approval of the long-term vision for the area and give the developers a flexible timeline under which to phase in the plan.

“When we first started the process, there wasn’t this master plan process in place,” Thompson said after Tuesday night’s workshop.

As part of the group’s renewed application, the developers submitted fresh renderings of how the property might look once the project is complete.

Thompson said components of the initial development plan that haven’t been changed, and thus still have their original city approvals, have been — or will soon be — started. Among them are road improvements, waterfront cleanup and the renovation of a 34,000-square-foot brick building on the property.

As a result of the extra acreage acquired through the Suburban Propane deal, Thompson said the parking garage and event center are now envisioned to be closer to the railroad lines across the northeastern edge of the property.

Like the four-tower Midtown project in Bayside, the high-profile Thompson’s Point project is seen as a major change for one of the city’s most recognizable properties, a 30-plus-acre Fore River peninsula that serves as Portland’s welcome mat to highway drivers from the south.

In August 2013, the startup Circus Conservatory of America — billed as the nation’s first college of the circus arts — was named an anchor tenant for the project alongside the Red Claws, a Development League affiliate of the Boston Celtics.

Thompson, who said he has no historical family tie to the property despite having the same name as the point, said he hopes construction of the circus school, a hotel and restaurant can begin as early as this summer or fall.

When the developers return to the Planning Board, likely in March, they will respond to questions they fielded from city officials Tuesday, such as concerns about increases in traffic in the area resulting from the new activity generated by the project.

According to a report by economist Chuck Lawton of the research group Planning Decisions, the project when completed will generate $31.3 million in new annual sales for Maine businesses, 455 permanent jobs and $11 million in yearly wages.

During construction, the development will additionally support 1,230 jobs and $49 million in wages.