BRUNSWICK, Maine — Bowdoin College announced Wednesday that its endowment surpassed $1 billion this year for the first time.

The Bowdoin Daily Sun, the college’s daily newsletter, reported that Bowdoin President Barry Mills attributed the 16 percent investment return to “enormous generosity” from alumni, parents and friends, as well as “the prudent and brilliant management of our endowment” by administration and an investment committee.

“Our college must be affordable to the middle class of America,” Mills told the Bowdoin Daily Sun. “Since [our] ever increasing costs are not matched by an ability to charge parents and families additional fees, we must rely more and more on [income from] the endowment to meet our expenses.”

Mills was traveling Wednesday and unavailable for comment.

Bowdoin College spokesman Scott Hood said the college received $38.1 million from the $1,038,640,000 endowment this year. Of that, $17 million funded financial aid, with the remainder supporting operational costs.

Tuition, room, board and fees at Bowdoin total $57,834, although the average financial aid grant is $36,840, according to the Hood.

Comparably, Bates College’s estimated endowment this year is $232.7 million, although a final figure is not yet available, spokesman Roland Adams said Wednesday. Tuition, room, board and fees at the Lewiston school total $58,950.

At Colby College in Waterville, the 2013-2014 tuition, room, board and fees are $57,510, according to spokesman Stephen Collins, and the college’s 2012 endowment was $600 million. Collins said the 2013 endowment figure would not be available until late October.

Hood declined to say whether the value of Bowdoin’s endowment would affect the cost of tuition in coming years. He said the value of the endowment does not affect the college’s plans to expand.

“The college has no plans to expand beyond the incremental growth we have seen over the past two decades,” Hood said in an email.

Hood said the value of the endowment would not affect the college’s investment in fossil fuels — an issue of contention in February after some 500 Bowdoin students signed a petition calling for divestment.

Speaking at the time for student group Bowdoin Climate Action, then-sophomore Hugh Radcliffe of Austin, Texas, said that discussions about divestment with Mills were “not the most constructive,” and the administration was “not very transparent at all.”

At the time, Radcliffe said Mills “questions the financial ability of the college to divest and not harm financial aid. He’s in favor of lowering the college’s carbon footprint but not [through divesting] … he’s framing it in terms of, ‘If we divest, it may harm financial aid,’ which we disagree [with].”

“The $1 billion mark is important and impressive,” Hood said, in part, in an email Wednesday. “The investment return rate of 16 percent is also very important news. This puts Bowdoin at the very top of our peers [top 5 percent], nationally. This success says to our generous donors that Bowdoin has a strong and consistent record of managing their gifts extremely well, growing them, and putting them to very good use in support of the college.”

In 2012, Bowdoin’s $902.3 million endowment ranked 82nd among U.S. and Canadian institutions and 13th in New England, according to the National Association of College and University Business Officers.