LOS ANGELES — The extramarital affair between Los Angeles’s mayor, Antonio Villaraigosa, and a newscaster for Telemundo has created a new set of complications for the broadcaster’s corporate parent, NBC Universal — and possibly the mayor himself.

Even as its Spanish-language subsidiary is poised to decide the future of Mirthala Salinas, the now-suspended reporter who embarked on a romantic relationship with Mr. Villaraigosa while she reported on him, NBC Universal is proceeding with a massive $3-billion development plan that city officials must ultimately approve. Although Telemundo executives hold the key to the career of Ms. Salinas, now the subject of an internal investigation into whether she compromised the company’s journalistic mission, Mr. Villaraigosa holds his own considerable power over NBC Universal. The entertainment conglomerate very likely will need Mr. Villaraigosa’s help to navigate the city’s approval process as it spends the next year pushing its Universal City Vision Plan, a concept the mayor embraced seven months ago.

The first public discussion of the Universal City Vision Plan, a series of projects that would bring 2,900 new homes and 1.6 million square feet of new commercial space, will be held Wednesday, when residents will be asked to describe the environmental issues they want reviewed. But neighbors who live near Universal City have begun arguing that the mayor’s relationship with Ms. Salinas raises new questions about his ties to the broadcasting company — and whether he has his own conflict of interest.

“The only one who knows whether there is a conflict is the mayor, and if there is, the mayor needs to acknowledge it and recuse himself,” a nearby resident who is on a panel reviewing part of Universal City’s development plans, Richard Bogy, said.

The president of the Greater Toluca Lake Neighborhood Council near Universal City, Terry Davis, suggested that Mr. Villaraigosa ask the city’s Ethics Commission to determine whether the mayor has any conflict of interest regarding the development plan. “We’re talking a huge project, a 20-year project that will irreparably affect a community, and we need to know that it is all above board,” she said.

Telemundo could end its review of Ms. Salinas by allowing her to keep her job as an anchor, by reassigning her to another program or affiliate, or even by letting her leave with a substantial severance package. Any of those decisions could be greeted positively or negatively by Mr. Villaraigosa, who has been publicly promoting NBC Universal’s project for seven months.

Mr. Villaraigosa’s aides would not say if the mayor will handle the Universal City project any differently in the coming months, saying they do not comment on hypothetical situations. But the mayor himself said this week that he sees nothing awkward about the overlapping relationships involving his girlfriend, her bosses, and the parent company seeking approval for a huge development project.

“I think that they have to act in accordance with their corporate rules and regulations, and I have to act in a way that is separate and apart from all that,” the mayor said at a ribbon-cutting for a new restaurant at Universal CityWalk. Universal Studios, the NBC Universal unit pushing the development plan, had a sharper response. “These are completely unrelated issues, and obviously one has no bearing on the other,” a spokeswoman, Cindy Gardner, said in a statement.

Ms. Salinas has been on paid leave since July 5, when Telemundo announced that it would conduct a review of the work she performed while dating the mayor.

But Mr. Villaraigosa mentioned NBC Universal as recently as Monday, when he was asked by reporters why Telemundo had not contacted him as part of its internal review of Ms. Salinas. The mayor responded by suggesting that reporters put the question to NBC Universal.

Among elected officials in Los Angeles, Mr. Villaraigosa is by far the biggest champion of NBC Universal’s plan for Universal City, which ranks among the region’s largest development projects. The plan, which calls for new homes, production facilities, office buildings, and a 500-room hotel, is rivaled only by two projects in downtown Los Angeles — the proposed Grand Avenue development and L.A. Live, a hotel and entertainment complex being built just north of Staples Center. Mr. Villaraigosa spoke vigorously in favor of the Universal City project in December, when NBC Universal executives announced components of the development plan. On Wednesday, Mr. Villaraigosa repeated his support, calling it a critical economic development project.

By comparison, City Councilman Tom LaBonge, whose district includes neighborhoods around Universal City, and Los Angeles County Supervisor Zev Yaroslavsky have characterized NBC Universal’s plan as too large, saying the resulting traffic would threaten to overwhelm the region’s roads.