HAVERHILL — The city's downtown explosion — from hundreds of new apartments to an influx of restaurants — has caught the eye of one of the region's most successful businessmen.

Salvatore Lupoli, owner of the Sal's Pizza chain, has been touring downtown as he considers opening a business there.

Lupoli operates food businesses throughout the area, including Salvatore's Restaurant in Lawrence, cafe-style restaurants, meals to go businesses and even sandwich shops.

Lupoli was in Haverhill yesterday on what he called a "search and discovery" mission to learn more about the downtown and how one of his businesses might fit in. He already has a Sal's Pizza just north of downtown.

The heart of Haverhill is teeming with development, including more than 800 apartments and condominiums under construction or planned for old shoe factories, and several new restaurants, lounges and shops. A 300-foot boardwalk will be built along the Merrimack River and a parking deck-transportation center also is planned. One of the city's two commuter rail stops is downtown.

"The mayor contacted me and expressed his excitement about the downtown and its revitalization," Lupoli said yesterday as he walked along Merrimack Street. "We're looking at several pieces of property but we have not made any decisions yet. We want to sit down with the mayor and planning director to explore our options. We're looking at many ideas."

Mayor James Fiorentini said he would welcome a Lupoli business, such as a restaurant. Fiorentini said his dream is for downtown to become "the best restaurant zone north of the North End."

"The North End has about 20 times the number of restaurants we have," Fiorentini said. "I would not want to saturate the downtown with bars, but we welcome more food places."

Lupoli said he has visited with several downtown businesses to get a feel for where the area is going and what it needs to grow and become a mecca for shopping, dining and various services.

"I'm feeling very positive about the downtown, although the city needs to fill some of these vacant buildings," he said. "Bring in people, give them quality housing and they'll come downtown."

Lupoli said Fiorentini is one of the driving forces in the revitalization of downtown and that large housing complexes such as The Cordovan, with 136 apartments, and the Forest City project with more than 300 units, can only benefit local businesses with the hundreds of new residents that have moved in and are expected to settle there.