After months of discussions with city officials, NBC Universal Inc. is proposing a major expansion and upgrade of its Universal City property, including 2,900 apartments, lofts and condominiums; additional office space; and an upgrade of its studio and entertainment facilities.

Mayor Antonio Villaraigosa and Universal Studios Inc. President Ron Meyer are expected to announce the 25-year plan this afternoon at the Universal Studios Hollywood theme park.

The plan specifically calls for a 124-acre development of 2,900 homes on an open hillside adjacent to Universal Studios. Some 35 acres would be set aside for open space with the residences grouped into three “villages,” according to a press release issued by NBC Universal, a unit of General Electric Co.

NBC Universal plans to discuss with the Metropolitan Transportation Authority building a studio and office campus at the Universal City MTA Station. Thomas Properties Group Inc., which served as an advisor to NBC Universal on the plan, would develop the complex, which would include 450,000 square feet of office space and 200,000 square feet of production facilities. A second 400,000-square-foot office building could also be built by Thomas Properties.

A refreshed Universal Studios theme park and City Walk is another key to the plan. NBC Universal may expand its City Walk attraction with new retail and dining facilities, as well as a 100,000 square foot live production studio where guests become part of the action. A 3,000 square foot enclosed entertainment venue might also be built, along with new attractions for an improved Studio Tour. Upgrades to the studio’s film and television production facilities would include new sets, post-production facilities and sound stages, among other features.

In order to handle the increased traffic that the new development would bring, NBC Universal is proposing an internal shuttle system, new dedicated access to the Hollywood (101) Freeway, a direct connection to Forest Lawn Drive and improvement to Barham Boulevard, among other ideas.

The company will file applications for the plan with the city and Los Angeles County, and will begin working with the MTA and the community, the release stated.