Maine’s top-selling residential real estate agent in 2015, who closed on more than $100 million in sales, has sold off the bulk of his RE/MAX franchises in Portland and Portsmouth, New Hampshire, to focus on his own personal clients.

David Banks, who founded RE/MAX By the Bay in 1994 and grew it into one of Maine’s largest real estate franchises, said he had been thinking about selling the downtown Portland and Portsmouth businesses for a couple of years. As part of the sale, Banks will retain the RE/MAX By the Bay brand in Portland, his clients, his personal staff and an office on Veranda Street near the Falmouth town line.

“I want to focus 100 percent of my time spending more time with my clients and growing my personal real estate business,” Banks said.

The rest of the operation has been sold for an undisclosed sum to RE/MAX By the Bay executives Rachel Reed and Derrick Buckspan. In Portland, they have renamed the franchise RE/MAX Shoreline, but the Portsmouth franchise will continue to operate as RE/MAX By the Bay.

In a related turn, seven former RE/MAX By the Bay agents left the firm in December to open a Portland office of the Portsmouth-based Bean Group real estate agency.

RE/MAX, like other large, national real estate franchisers, has a complex structure that involves individual franchise owners, staff and independent contractors. Most RE/MAX agents are contractors who share branding and support staff under the umbrella of a local franchise but act in many ways as individual business owners.

Banks said By the Bay had as many as 60 agents under his ownership, and that it was difficult to meet their needs while serving his own clients, which is what he enjoys doing most.

On Thursday, Banks said he was feeling “a lot less stress now because I’m not worried about all the different offices.”

In 2015, Banks sold 254 homes with an aggregate value of $116 million, far more than any other agent in Maine. He has a staff of 10 that performs many of the tasks associated with buying and selling homes, while Banks handles all of the pricing and sale negotiations.

“It’s just a great business to be in,” he said. “(You get) the satisfaction to know that you’ve helped someone selling a property.”

At the RE/MAX Shoreline office on Middle Street in the Old Port, co-owner and broker Buckspan said it made sense for Banks to retain the By the Bay brand in Portland.

“He had put his lifeblood into that name, and he wanted to keep it,” Buckspan said.

Under the sale agreement, Banks may not contract with other agents to grow the business into a traditional franchise. However, there are no restrictions on how many support staff members he may hire, or the number of homes he can sell.

Reed said the change to a new name is a positive for the Shoreline franchise, where some agents had become discouraged and the environment highly competitive. She sees the shakeup as a fresh start.

“A new name gives us an immediate opportunity to change the culture,” Reed said, adding that the new owners’ goal is to foster a spirit of collaboration among their roughly 40 agents in Maine and New Hampshire.

Buckspan described Banks as a benevolent owner who was fun to work with, but who was spread thin between his own clientele and the demands of owning a large real estate franchise.

“He certainly tried. He was knowledgeable and he would help if he could,” Buckspan said. “His passion was in sales.”

David Marsden is one of the former RE/MAX By the Bay agents who left the franchise and opened the Bean Group office on Jan. 1 at 6 City Center in downtown Portland. He is the office’s associate broker.

Bean Group is an independently owned agency founded in Portsmouth by Michael Bean that has 15 offices and 350 agents in northern New England, Marsden said.

“They’ve been considering opening a Portland office for a long time,” he said.

Marsden said the former RE/MAX agents were impressed with the way Bean uses technology in innovative ways to promote its listings and assist clients.

“It’s very technology-oriented and forward-thinking, ahead of many traditional, brick-and-mortar real estate companies,” he said.