The retirement businesses of Putnam Investments of Boston and Great-West Financial of Denver will be merged under a plan announced today by the firms’ parent company, Great-West Lifeco U.S.

It was also revealed that Robert Reynolds, Putnam’s president and CEO, will take on the same leadership role with Great-West Lifeco U.S. and Great-West Financial. All three companies are owned by Winnipeg, Canada-based Great-West Lifeco Inc.

Executives described the restructuring as an attempt to consolidate the two retirement businesses to capture expected growth in the U.S. 401(k) retirement account market.

Together, the retirement businesses of Putnam and Great-West Financial consist of about $220 billion in assets under administration and 5 million participants, according to Reynolds.

While Putnam’s 401(k) business has focused on medium to large businesses, he said, Great-Western Financial has been strong in the small- to medium-sized market, including government 457 plans and non-profit 403(b) entities.

“Now, by pulling the two units together, there is total coverage of the 401(k) market,” Reynolds said during a press briefing announcing the move. "As they partner more closely, each will become an even more competitive force."

The combined retirement services entities will reside within Great-West Financial, according to the company.

Executives added that there are no plans for layoffs during the integration, and that it is more likely that the number of jobs will increase as a result of the merger.

“Because of the growth we are looking at, we would actually be looking to add people over time,” Reynolds said.

Paul Mahon, president and CEO of Great-West Lifeco, added that the merger of the retirement units will leverage the asset management expertise of Putnam and the insurance products and services of Great-West Financial.

“We have no goals of cost reduction through this,” Mahon said. “This is a growth play. … This play is about how do we grow more effectively and at a higher rate in the U.S.”

Great-West Lifeco executives noted that Putnam and Great-West Financial will remain separate subsidiaries, and that it is only the retirement services portions of their businesses that are being merged.

No decision has been made on whether the integration of the two units will result in any branding changes, Reynolds added.

Reynolds will take over as Great-West Financial president and CEO in May, after the retirement of Mitchell Graye, according to Great-West Lifeco.