Apple Inc plans to build a circular spaceship building in hometown Cupertino that will hold 12,000 employees -- and be the best office building in the world, Chief Executive Steve Jobs said.

The ailing chief of Apple, formally on leave from the company, made his second public appearance in two days late on Tuesday to show off plans to the Cupertino city council.

It's a little like a spaceship landed, said Jobs, showing off a four-story, circular building with a massive interior courtyard on a 150-acre piece of landscaped land.

There is not a straight piece of glass in the building, he said. We know how to make the biggest pieces of glass in the world for architectural use.

Apple has grown like a weed Jobs said, and needs a place to put roughly 12,000 people. The massive new structure would be in addition to the main campus at 1 Infinite Loop.

That's rather odd, 12,000 people in a building, in one building. But we've seen these office parks with lots of buildings, and they get pretty boring pretty fast, so we'd like to do something better than that, he said.

I do think we have a shot at building the best office building in the world, he added, showing off sketches.

He quickly shot down questions from city council members, avoiding a request to give free Wi-Fi to the city and arguing that the increase in workers at the site would not be significant enough to require any traffic mitigation efforts.

Landscaping will include trees, native plants and apricot orchards, a throwback to the agricultural heritage of Silicon Valley when Jobs was growing up.

Apple bought most of the land from Hewlett Packard Co, where Jobs got one of his first summer jobs after calling up his idol and HP founder Bill Hewlett, to ask for spare parts. Hewlett and Packard bought the main parcel, he said.

(Reporting by Peter Henderson and Poornima Gupta)