I've said time and time again that one of the most important things to look for in a mutual fund is a manager or management team that has been in place for a number of years. You want to see how the manager responds to all market environments, both good and bad.

Unfortunately, many funds have practically a revolving door when it comes to managers. However, there are a handful of funds that can boast a seasoned manager whose tenure can be measured in decades rather than years. And Harbor International Fund (HIINX) is one such gem.

A top-notch skipper
Harbor International is headed up by Hakan Castegren, who has been at the helm since 1987. This December will mark his 20th year with the fund. Castegren is also the third-longest-serving manager of any international stock fund around, according to Morningstar data. In a world dominated by short-term results and even shorter attention spans, that kind of longevity is impressive.

Castegren is supported by an experienced team of analysts who scour the international waters for undervalued stocks with low price-to-earnings ratios and a favorable margin expansion outlook. The team tends to focus on large-cap foreign blue-chips such as ABB Ltd. (NYSE:ABB), BHP Billiton (NYSE:BHP), Petroleo Brasileiro (NYSE:PBR), and Novo Nordisk (NYSE:NVO). Turnover here is a low 12%, so many of these names stay in the portfolio for quite some time.

Harbor International's value leanings are reflected in the fund's sector weightings, which currently skew heavily toward financials (28% of assets) and industrial materials (26% of assets). The fund is light in the more growth-oriented sectors, with no holdings in software or media, and about 3% of the portfolio in hardware and telecom. The United Kingdom, Japan, and France make up Harbor International's largest country allocations, each with about 13% of the portfolio. The fund also devotes almost one-fifth of its assets to emerging market countries such as Brazil, China, and Malaysia.

Pretty performance picture
Harbor International has managed to amass an impressive track record over its nearly 20-year life. The fund has outperformed the MSCI EAFE benchmark and its foreign peers most of those years. The fund boasts a 15-year annualized return through August 2007 of 14.2%, compared to just 8.9% for the EAFE Index. Harbor's 15-year return number places it among the top 8% of foreign large value funds over that time period.

Harbor will tend to lag its peers during growth-led environments. For instance, the fund trailed the MSCI EAFE during 1998 and 1999, two rather speculative years. But Harbor International shows its strengths during market downturns. The fund beat the EAFE benchmark by roughly 9% in 2000, 2001, and again in 2002. Furthermore, the fund is remarkably consistent. Throughout the fund's 20-year history, there have been only five years when it failed to land in the top half of all large foreign value funds.

Fund expenses are very reasonable here, clocking in at 1.24%, far below the average for most foreign stock funds. All in all, there's really not much to quibble about with this fund.

The only potential concern would be about what will happen when Castegren decides to retire. The fund has flourished under his watch and, although he has a strong team, it is unclear whether his leaving would mean substantial changes for the fund.

At any rate, that day could be far off, and it is no reason why investors should not own this terrific fund now. If there is a place in your portfolio for a core international fund, Harbor International is probably one of the best choices out there to fill that position.

Related articles:

No matter which fund family you are interested in, you need to know which funds are the best fit for your portfolio. This information is waiting for you in the Motley Fool Champion Funds newsletter. Start your free, 30-day trial today.

Fool contributor Amanda Kish lives in Rochester, N.Y., and does not own shares of any of the companies or funds mentioned herein. Petroleo Brasileiro is an Income Investor recommendation. The Fool's disclosure policy has been going strong for many years.