Updated at 10:54 p.m.

CHICAGO, Illinois -- New designs for Cleveland's proposed medical mart call for four stories wrapped in glass and centered around an atrium reminiscent of downtown's traditional arcades.

"It's indoor space that can be used year-round," Rafael Vi

n

oly, of Seattle-based LMN Architects, said at a presentation Tuesday in Chicago.

Developer MMPI unveiled the latest drawings during the NeoCon World's Trade Fair furniture show. Vi

n

oly is a nephew of the New York-based, Uruguayan-born architect of the same name who designed the expansion and renovation of the Cleveland Museum of Art.

The Seattle architect described the mart building, envisioned for the northeast corner of St. Clair Avenue and Ontario Street in Cleveland, as a 200,000-square-foot structure featuring showrooms and meeting space on the ground floor and showrooms of up to 6,500 square feet on the upper floors.

The building will connect to a proposed new L-shaped convention center below Malls B and C.

Cuyahoga County and MMPI plan to break ground on the $425 million, taxpayer-financed mart and convention center in October and to open the mart in 2013.

So far, MMPI has tentative commitments from 24 companies to showcase large medical furniture and equipment, said MMPI Vice President Mark Falanga.

Landscape architects were not at the presentation, but Vi

n

oly said the underground convention center is being designed to withstand loads of large gatherings on the parklike mall above.

"In general, it's analogous to Millennium Park," he said, naming the Chicago tourist draw Cleveland boosters would like to emulate on the mall.

To reach this Plain Dealer reporter: ljohnsto@plaind.com, 216-999-4115