After years of delays, the New York grocery chain Wegmans is opening its first Massachusetts store in Northborough, where it is planning a 135,000-square-foot behemoth that will rival the state's largest supermarkets.

The store will anchor a $100 million shopping and residential complex called Northborough Crossing, which will include more than 380 homes, a Kohl's, Golf Town, T.J. Maxx, and Toys `R' Us, among other stores. Developers Brendon Properties and New England Development recently began construction, helping to break a private-sector building slump that has stalled large projects across the state.

While the construction slowdown has hurt the economy, it has also created opportunities for retail giants such as Wegmans, which can seize on lower real estate costs to expand into new markets. The grocery store, known for its huge prepared foods section and wide selection of high-quality generic products, is seeking to open several additional locations in Massachusetts, although only one other location, in Westwood, is currently planned. The Northborough store is scheduled to open next fall.

"Over the next five to seven years, we might have half a dozen locations in Massachusetts," said Ralph Uttaro, vice president of real estate development for Wegmans. "We're looking for high-density areas with high levels of income and education."

Wegmans is seeking a license to sell beer and wine, Uttaro said, and will have its typical variety of international foods and specialty products, including a section with dozens of imported cheeses.

The chain, which now operates 77 stores in the eastern United States, was initially slated to open its first store in another New England Development project in Westwood. But that project, a 4.5 million-square-foot minicity called Westwood Station, stalled after it struggled to generate funding in the down economy. New England Development is now working to resurrect the project with Eastern Real Estate LLC, which bought the development rights from a prior partner, Cabot, Cabot & Forbes.

In Northborough, however, construction of the open-air shopping complex at the intersection of routes 9 and 20 is now moving forward. The project, previously called The Loop and later Shops 9@20, suffered its own financial difficulties and was delayed for more than two years, but began to gather momentum in recent months. Lieutenant Governor Timothy P. Murray is scheduled to tour the 175-acre development site tomorrow.

"We're seeing an increasing level of [development] activity, and we want to accelerate that," Murray said yesterday. The Northborough project is being built without any state tax breaks or financial assistance for road upgrades or other infrastructure improvements, officials said.

An executive with New England Development said the introduction of Wegmans has been a driving force behind the project, which has secured tenants for 90 percent of its 600,000 square feet of retail space.

"We see them as a huge draw," said Douglass Karp, a vice president of the Newton-based firm. "They tend to attract people from almost 30 miles out."

Wegmans' retail formula is to build big and offer something for everyone. Its stores typically range in size from 120,000 to 140,000 square feet - a typical supermarket is 30,000 to 50,000 square feet - and it offers products ranging from caviar and mousse truffee to $6 prepared meals such as breaded pork chops and chicken marsala.

"Anywhere they go they attract a lot of attention and loyalty," said Jon Hurst, president of the Retailers Association of Massachusetts. "As the economy grows and consumers get more confident, companies like Wegmans see real opportunity."

Uttaro, the chain's head of real estate development, said the Northborough location will include in-store seating and a restaurant where shoppers can dine on prepared foods from pizza to sushi. Beyond the Westwood project, he said the store has not yet settled on its next location in Massachusetts.

"A lot of it depends on site availability," he said. "With our size and parking requirements, there aren't opportunities on every corner."