"Allstate monitored the progress in the market and kept a close eye on regulation," he says. "We feel it's the right time for a brick-and-mortar presence in Massachusetts."

Conner says Allstate will look to recruit agency owners in the state, and says the company is willing to consider candidates from outside the insurance world. The insurer will seek entrepreneurs with management experience from various branches of the business world, Conner explains. 

The insurer actually reentered the market in 2009, using agents in the neighboring states of Connecticut, Rhode Island and New Hampshire as well as direct sales.

Since then, Allstate has accumulated about 1.4 percent of the market. The Mapfre North America Group led all private passenger auto insurers with a 28.4 percent market share in 2011, according to A.M. Best Co.

There is no exact goal for increasing market share in the state, Conner says, but an "aggressive ramp-up" in the state is planned for 2013, he adds.

"It takes a while to get the brand reintroduced," says Conner. "Our initial efforts have been well-received. We think we can grow significantly."

Allstate joins a number of insurers who have found the Massachusetts auto-insurance market much more appealing with managed competition. Geico and Progressive have rejoined the fray as well.