Tucked inside an old building that used to house a tire maker, new high-tech businesses are quietly rolling out everything from synthetic bones to wireless, portable electrocardiogram machines.

The city of Akron held an open house Thursday to show off its expanded, renamed business incubator, now called the Akron Global Business Accelerator.

The venture, previously known as the Akron Industrial Incubator, is located in a city-owned building on Main Street that used to be part of the sprawling B.F. Goodrich complex now known as Canal Place.

A $1.7 million federal grant funded a renovation project that allowed the city to open up several more floors of the building to start-up businesses.

The initiative allows entrepreneurs to get free support services and rent space for about 30 percent to 40 percent lower than typical rates in the market.

The goal is to help those businesses get started and eventually graduate from the location and branch out into their own location in the community, Akron Mayor Don Plusquellic said.

With the accelerator's expansion, the city can ''provide for the next generation of businesses and entrepreneurs and accelerating their growth,'' Plusquellic said. '' . . . The whole idea of accelerating and helping a business to move forward is why we renamed it.''

Ben Shappley, chief executive of SpineMatrix Inc., was among several business leaders who attended the open house to share their experiences in the Akron Global Business Accelerator.

SpineMatrix decided to move into the building in January largely because it offered a good location with affordable rent, Shappley said.

The company is developing a test for neuromuscular activity that can be used by orthopedic surgeons and neurosurgeons trying to access the cause of their patients' back pain.

''It's very economical,'' Shappley said of the accelerator. ''That's very important to us so we don't have to dilute the company's funding.''

Since the business development project launched in 1983, the venture has helped 64 companies establish other locations in the community and boost their collective employment from 125 to 747, according to the city.

Currently, 35 businesses with a total of 142 employees are located within the Akron Global Business Accelerator. Several other entrepreneurs have expressed interest in soon locating there, Plusquellic said.

Last year, businesses in the accelerator generated payroll taxes of $129,400 and private-sector investment totaling about $9 million, said Mike Lehere, the Akron Global Business Accelerator's chief executive.

The city's total investment in the project has been about $8 million.

''That is a success story that I'm proud of,'' Plusquellic said.

State grant money and rents from the tenants pay for the bulk of the venture's $700,000 annual operating budget, Lehere said.

The expansion of the Akron Global Business Accelerator is one of several steps the city has taken in recent years to diversify and grow the area's economy.

Last year, the city designated a biomedical corridor to lure medical-related businesses near its three hospitals: Akron City Hospital, Akron General Medical Center and Akron Children's Hospital.

The city also has contributed to an incubator in Israel known as Targetech. Any Israeli companies that emerge from the incubator, in return, have agreed to base their U.S. headquarters in Akron.