SPRINGFIELD --MassMutual announced plans Thursday for a major expansion in Massachusetts including a $300 million investment and 2,000 jobs to the Commonwealth over the next four years.

Those 2,000 jobs include 1,500 at corporate headquarters in Springfield and 500 at a new Boston campus on Fan Pier, which the company plans to build.

The move comes amid a trend in Springfield where MassMutual has laid off hundreds in recent years and has moved jobs in its Barings subsidiary elsewhere.

MassMutual was founded in Springfield on May 15, 1851 and is owned by policy holders. It's No. 77 on the Fortune 500 list with $675 billion in assets under management.

As part of this plan, MassMutual is expanding in Springfield and expects to grow its workforce at its corporate headquarters by approximately 50 percent, MassMutual said on Thursday.

The Springfield expansion will bring the total number of employees in Springfield to approximately 4,500 by 2021 from about 3,000 now, according to the company.

MassMutual will close its offices just across the border in Enfield, Connecticut, company spokesman James Lacey said. About 1,500 people work there and most of jobs will move to Springfield.

MassMutual is also closing offices in Charlotte, North Carolina, Somerset, New Jersey, Memphis, Tenn., and Johnstown, Pennsylvania.

The Enfield offices, like the Springfield headquarters, are only at about 60 percent occupancy, Lacey said.

"It just didn't make sense to have two offices, each 60 percent full, less than 10 miles from each other," Lacey said.

MassMutual has not yet made specific decisions on which employees will move where, Lacey said. Employees were informed of the general outline of MassMutual's plans Thursday.

MassMutual does plan to spend $50 million over the next five years in renovations and construction at the Springfield headquarters.

Lacey said MassMutual hasn't decided on what it will do with the Enfield campus. It acquired the Enfield complex from The Phoenix Cos. Inc. in 2004.

In 2014, MassMutual unveiled the more than $38 million renovation at the Enfield campus which was at the time the primary location for the company's retirement services and workplace insurance businesses.

Massachusetts Gov. Charlie Baker hinted at the news Thursday morning, without naming MassMutual, while speaking at a Greater Boston Chamber of Commerce Breakfast.

MassMutual said it is expanding in Massachusetts because the state provides the company with everything it needs to continue to best serve its policyowners in the future, including: a highly skilled workforce, including a rich pipeline of talent from the state's best-in-class network of higher education institutions; robust local economies; convenient access to transportation, and a diversity of communities, including the best of both metropolitan and suburban locations.

While starting with 500 employees, the Boston Fan Pier offices will eventually grow to 1,000, the company said. It will be a multi-story office structure - which will be in excess of 300,000 square feet - and will be situated on an undeveloped parcel owned by MassMutual, with MassMutual as its primary tenant.

"Following a thorough strategic assessment of our operations and footprint, we concluded that our home state of Massachusetts is the best place for us to grow and thrive over the long term," said Roger Crandall, MassMutual Chairman, President and CEO. "We have deep roots and a supportive community in our hometown of Springfield, and we will continue to invest and grow our workforce in the city."

The Boston jobs will be located there to take advantage of the city 's tech industry with access to financial markets and digital talent.

"Our highly educated and skilled workforce helps the Commonwealth and great companies like MassMutual continue to lead the nation in a number of competitive categories," Baker said in a statement provided by MassMutual. "We are proud MassMutual has called the Commonwealth home for over 165 years and we look forward to what their investments in Western and Eastern Massachusetts will mean for Massachusetts, our economy and their employees."

MassMutual will receive a package of incentives valued at approximately $46 million from the Commonwealth, the largest commitment ever made to a Springfield-based company.

Those incentives are contingent upon MassMutual meeting its job-creation obligation of adding 2,000 jobs in Massachusetts. The job growth will result from new hires as well as relocation from other MassMutual sites to both Springfield and Boston, according to the company.

Over time, MassMutual plans to consolidate certain facilities in other parts of the country, moving positions to its Springfield and Boston campuses. The company currently expects to retain offices in Amherst, New York City and Phoenix, which provide access to specific talent pools and business solutions.

"My administration has been working hard to create an environment that encourages job growth and today's announcement illustrates that through collaboration, we can find constructive solutions to support our communities for the long-term," Springfield Mayor Domenic J. Sarno is quoted as saying.

Boston Mayor Martin J. Walsh also shared his excitement for the company's pending growth in his city.

"We are thrilled to have MassMutual expand its presence and build a new campus on Fan Pier," Walsh said. "MassMutual's decision to grow in Boston will give the company greater access to the growing technology and financial services industries in our city and enhance its ability to attract the best available talent. I am delighted another major employer has decided the City of Boston can contribute to its successful future."

U.S. Rep. Richard E. Neal, D-Springfield, hailed the impact MassMutual's decision will have on the regional economy.

"This is terrific news for our community and state. Mass Mutual has made its home in Springfield for nearly 170 years. The company has been a solid corporate citizen that continues to invest its considerable resources locally. Today's announcement that they are expanding their workforce in the city by 1,500 employees will have a significant and immediate impact on the region's economy. I welcome Mass Mutual's decision and believe it is vote of confidence in the City of Springfield and the Commonwealth of Massachusetts."

Lt. Gov. Karyn Polito hailed the news while speaking Thursday following a luncheon of the Webster-Dudley-Oxford Chamber of Commerce.

"MassMutual has had a very strong presence here in Massachusetts the jobs here in our commonwealth are very important to us. We're very pleased to see the expansion and to see them retain such a strong foothold in Springfield where they have long been an incredible business partner to the city, to the region. And we are thrilled that they would expand here in Massachusetts."

State Sens. Eric P. Lesser, D-Longmeadow, and James T. Welch, D-West Springfield, praised the decision. Both mens' districts include sections of Springfield.

"This is very good news, to see MassMutual doubling down on its investment in Massachusetts. MassMutual is a proud Springfield company founded here nearly 200 years ago, and its decision announced today sends a clear signal that Springfield and Western Massachusetts are open for business!" Lesser said.

Welch said, "MassMutual's announcement is a sign of just how strong and business friendly the economy is here in the Commonwealth. As talks about companies moving jobs to Massachusetts continually center around Boston, it is refreshing to see a company reinforce its Western Mass roots."

This is a developing story which will be updated as the reporting progresses.

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