A larger Indiana Convention Center should enable Indianapolis convention bookers to attract and retain the "whopper" events that were showcased to justify the $275 million addition that officially opens Thursday.

One of the most obvious examples is the locally based Custom Electronic Design & Installation Association, which will bring its fall trade show back to Indianapolis in September and again in 2012. CEDIA, which attracts 25,000 visitors, left the city in 2005 because it had outgrown the center and is making good on a promise to return after the expansion is finished.

But competition among cities is so stiff for those types of mega-conventions that smaller fish—corporate meetings that might attract 1,000 visitors or less—will be key to keeping the convention center adequately occupied.

“It’s understandable why [big conventions] command such fascination, because they are enormous engines of economic development,” said Steven Hacker,  president of the Dallas-based International Association of Exhibitions and Events. “That aside, the backbone of the industry is not those 200 events; it’s the 9,700-odd events that take place every year in the trade-show industry.”

Most convention center additions are constructed to accommodate multiple meetings simultaneously, industry experts said.

Indianapolis is no different. It’s the only way the Indianapolis Convention & Visitors Association can meet its growth goals to validate the expansion, departing ICVA CEO Don Welsh said during construction. ICVA currently is searching for a replacement for Welsh, who earlier this month accepted a similar position in Chicago.

ICVA typically hosts 20 large conventions annually. The target now is to increase that number by 10, while still putting an emphasis on luring more events of all sizes.

That’s evident in ICVA’s decision to devote more resources to luring smaller conferences, spokesman Chris Gahl said.

“We’ve added two salespeople deliberately focused on smaller-market meetings,” he said. “That’s a deliberate strategy.”

Those smaller conferences or corporate meetings often can be booked and held within the same year, whereas the large conventions are typically scheduled five to seven years in advance, and, in some instances, eight to 10 years, Gahl said.

Examples of smaller organizations booked this year include American Association of Community Colleges, Pediatric Endocrinology Nursing Society, Magnet Schools of America and National Coalition of 100 Black Women, each of which will draw fewer than 1,100 visitors to the city.

ICVA also plans to supplement large bookings by trying to attract corporate business mostly from the pharmaceutical, medical, life sciences and sports-related industries, Gahl said.

ICVA nearly doubled the amount of medical meetings it booked last year compared with 2009. Those meetings accounted for 19 percent of total conventions booked in 2010, up from 10 percent the previous year. That’s important because, although the conferences may only attract 100 visitors, the clientele is more upscale, Gahl said.

“By nature, these are doctors, physicians and researchers that spend more per day on average when they’re at a destination and tend to stay longer,” he said.

So far this year, ICVA has booked 253 meetings in 2011, some of which might attract just 50 people, compared to 401 last year. ICVA expects to exceed last year’s number, Gahl said.

But the real key indicator for growth is the amount of hotel room nights booked in a given year, Gahl said. ICVA last year booked 650,000 hotel room nights for 2010 and beyond. This year, its goal is 725,000—a nearly 12-percent increase.

The addition of the 1,005-room J.W. Marriott hotel, set to open Feb. 4 on the west edge of downtown, gives the city another advantage when courting conventions.

Once the hotel complex is finished, roughly 4,700 hotel rooms will be connected via skywalk to the convention center and Lucas Oil Stadium, which further encourages visitors to walk instead of drive to their destinations.

More hotel rooms not only gives the city leverage to host a large event such as the 2012 Super Bowl, but also more flexibility to accommodate multiple meetings concurrently.

“If you take a look at a typical convention center, good occupancy may be considered to be somewhere in the range of 65 to 70 percent,” Hacker said. “Any increase above that number that you can achieve is money in the bank.”

Nearly 350,000 square feet of exhibit space was added to the convention center, pushing it from 32nd largest in the United States to 16th. The facility, when combined with exhibit space at Lucas Oil Stadium, will have a total of 1.2 million square feet of exhibit and meeting space.

A ribbon-cutting ceremony marking the official opening of the expansion will be held at 10 a.m. Thursday in the three-story glass “cube” entrance on the building’s west side, at Capitol Avenue and Georgia Street.

Indiana Gov. Mitch Daniels and Indianapolis Mayor Greg Ballard are expected to speak at the event.

An open house will follow from 10:30 a.m. to 2 p.m.