PORTLAND — A tentative settlement of a four-year legal battle between Portland and Boston over a $2 million bequest from a prominent Maine family could pave the way for new trails and tree plantings at a popular Portland park.

In return for dropping its claim to the money willed by former Portland Mayor James Phinney Baxter and his son, former Maine Gov. Percival P. Baxter, Portland stands to receive $400,000 for improvements to the park around Back Cove.

The elder Baxter died in 1921 and left Boston $50,000. As soon as the invested funds reached $1 million, the money was to be used to build a pantheon — a kind of temple — honoring the first New England settlers. But Portland was to get the money if Boston did not build the monument within five years of reaching the $1 million mark, the will specified.

Baxter’s son, best known for donating the land that became Baxter State Park, boosted his father’s bequest with $200,000 when he died in 1969.

The legal dispute began after a student came across the wills in 1983. At issue was whether the $1 million threshold governed only the original bequest or the entire gift from father and son.

Last August, a judge sided with Boston’s argument that the wills should be interpreted separately. But the original bequest had reached $1 million, meaning Boston had five years to build the pantheon.

Portland City Manager Robert Ganley said officials decided to take the $400,000 now and let Boston have the rest to end the legal dispute — and get money that has been sitting in a trust for decades.

“At some point, you have to say, `How well are we going to come out of this, and what is the best solution?’ The lawyers recommended we do this, and we agreed,” said Ganley.

City Councilor Cheryl Leeman said spending the $400,000 for the Back Cove area — the city’s most heavily used park — is appropriate because James Phinney Baxter created the park by buying land around Back Cove and convincing other landowners to donate parcels to the city.

“If he were alive today, he would say this is where the money should go,” Leeman said.

Later this month, councilors plan to consider park improvements that could range from new tree plantings along Baxter Boulevard to separate trails around Back Cove for walkers and bicyclists.

For its part, Boston will not have to build the pantheon. The settlement agreement between the two cities calls for Boston to use its $1.6 million portion of the bequest for unspecified public projects and programs to promote understanding of immigrants who settled in New England.