Dec 5 (Reuters) - MFS Investment Management, the

Boston-based asset manager that unveiled the world's first

open-ended mutual fund a century ago, is making a foray into

exchange-traded funds with the launch of five ETFs on Thursday.

Three of the ETFs are tied to the stock market, while the

other two offer core bond and municipal bond exposure,

respectively, the firm said in a press release.

"This is not about launching a new business, but about

delivering our existing capabilities to investors in a new

vehicle or package, the ETF," Michael Roberge, CEO of MFS, told

Reuters.

Investors have piled nearly $1 trillion into ETFs this

year, with a booming U.S. stock market and a proliferation of

new products fueling the record inflow.

The popularity of ETFs has spurred traditional asset

management firms such as Fidelity and Invesco ( IVZ ) to launch

their own offerings in recent years to compete with industry

giants like State Street Global Advisors, Vanguard and BlackRock ( BLK )

.

While MFS was a very early mover in the mutual fund

business, launching the Massachusetts Investors Trust fund in

1924, it has been relatively slow to enter the increasingly

competitive ETF arena, analysts said.

"There are still some latecomers to this product that have

been slower and more cautious," said Bryan Armour, ETF analyst

at Morningstar. "As active ETFs have exploded in size, the

impetus for them to dedicate resources to ETFs has grown."

ETFs are more liquid than mutual funds, since they can be

traded on an exchange throughout the day, and more tax

efficient. They also tend to have lower management fees.

The five ETFs are MFS Active Value, MFS Active Growth,

MFS Active International, MFS Active Core Plus Bond and MFS

Active Intermediate Muni Bond. They mirror existing MFS

strategies, Roberge said.

Armour pointed to Tuesday's debut of the first ETF from

Harris Associates L.P., the Oakmark U.S. Large Cap ETF,

managed by Bill Nygren, as another recent example of a top

mutual fund name moving into ETFs.