The Irvine Co. has asked the city...

The Irvine Co. has asked the city of Newport Beach to approve plans for a major expansion of the posh Newport Center shopping and office building complex.

The company said that its latest plans for completion of the 600-acre regional complex--the third revision since the early 1970s--call for an expansion of approximately 15% of Fashion Island, the center’s retail hub.

Roger Seitz, the Irvine Co.’s vice president of planning and urban design, said the company hopes that the plan will enable “the center, Fashion Island in particular, to remain economically vital and competitive in the regional marketplace.”

The company proposes to add a 16-story office tower and two 12-story office buildings to the existing Newport Center office building complex, currently consisting of 14 major buildings. In addition, a series of one- and two-story office buildings would be developed on now-vacant land parcels within the center, and homes and apartments would be built on the center’s perimeter.

Seitz said the development of the remainder of the Newport Center area, including 75 acres within the center and 100 acres adjacent to it, would begin next year and be completed by the year 2000.

The Irvine Co. said the plan it has submitted to the city is “a working document . . . that is subject to further refinement during the course of extensive city review.” Company officials estimated that before the City Council votes on the project, the review process will take at least six months.