Webster Financial Corp. will take over three more former Citi branches this month, bumping up its total branch network in the Greater Boston area to 18, the company said this week.

The latest additions to its network are located in Chinatown, Harvard Square and Quincy.

“These three additional banking centers round out our recently announced Boston expansion, giving us instant critical mass to serve families and businesses in the city and close-in suburbs,” Chairman and CEO James C. Smith said in a statement. “This is great news because we will now be able to step into each of the 17 former Citibank banking centers in the market. We also look forward to welcoming the Citibank retail bankers who have agreed to join Webster, which will minimize disruption during the transition.”

The holding company for the $24 billion Webster Bank announced in December that it would be taking over 14 of the leasehold interests being vacated by Citibank. Sometime this month, Webster will open those branches under its own brand. It will not acquire any loans or deposits from Citi.

The Waterbury, Connecticut-based Webster first broke into the Boston market in 2009 with an office in the Financial District that focused largely on commercial business. Speaking to Banker & Tradesman last month, Smith said that Webster had about $1.3 billion in loans and more than $500 million in deposits in this market.

The company did not disclose the terms of the deal, but said it would most likely be dilutive to earnings this year, would likely break even next year and would be accretive to earnings after that.

Now that Webster has shored up those last three Citi branches, expect an aggressive marketing campaign in the months to come as it establishes an immediate critical mass in Boston.