Dallas' skyline could be in for big changes, thanks to one of the world's top architects.

Sir Norman Foster, the legendary British architect whose firm has designed some of the world's most compelling skyscrapers, is working on a tower for downtown Dallas.

Developer H. Ross Perot Jr.'s Hillwood real estate firm has hired London-based Foster + Partners to create concept plans for an almost 70-story tower on the northern edge of downtown.

The soaring glass-and-steel high-rise would be across Woodall Rodgers Freeway from the Perot Museum of Nature and Science.

Artist's renderings on display in the Perot family's new Dallas headquarters on Turtle Creek show a round building with three atrium areas and a lighted top.

The tower would be built at Field Street and Woodall Rodgers on the former Bank of America site, which Hillwood recently cleared for future construction.

"We have a million-square-foot tower planned," Perot said. "We have the rough renderings and this is what we want to build.

"With Sir Norman Foster as the architect, it's fabulous."

Hillwood is already showing the plans to prospective office tenants.

If the project moves ahead, it would be the tallest tower built in Dallas in more than three decades.

Foster's structures have transformed great cities around the globe.

Foster + Partners designed the Margot and Bill Winspear Opera House with its red drum-shaped performance hall in downtown Dallas. (Tom Fox/Staff Photographer)

Foster + Partners designed the bright-red Winspear Opera House in downtown Dallas.

The 81-year-old architect's torpedo-shaped tower in London is a favorite on the skyline. Locals have nicknamed it "The Gherkin."

Foster + Partners also designed the breathtaking glass-roofed courtyard at the British Museum.

In North America, the architect's credits include the Hearst Tower in Manhattan.

And Foster designed the 57-story Bow skyscraper in Calgary, Alberta, Canada for Dallas developer Jack Matthews. Some of the exterior design features for the proposed Hillwood tower are similar to the Bow.

Foster + Partners also did a skyscraper proposal for the Omni Dallas Hotel, but the project couldn't meet cost requirements.

"We are also working with Foster on a project in the United Arab Emirates," said developer Matthews. "They really do great stuff."

Adding the award-winning international architect to the team working on Hillwood's downtown tower should give the Perots a design edge in the competition for office tenants.

The recently completed McKinney & Olive tower, designed by famed architect Cesar Pelli, was almost fully leased when it opened recently.

For decades, Texas developers have turned to rock-star architectural firms to help their projects break out of the box.

And builders here have long had a hankering for round towers.

In the late 1960s, developers proposed building a 90-story skyscraper near Dallas City Hall that would have included a hotel, offices and shopping. But that project never made it off the drawing boards.

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