Exchange-traded funds offer a convenient way to invest in sectors or niches that interest you. If you'd like to add some international telecom stocks to your portfolio but don't have the time or expertise to hand-pick a few, the SPDR S&P International Telecommunications Sector ETF (NYSEMKT: IST) could save you a lot of trouble. Instead of trying to figure out which companies will perform best, you can use this ETF to invest in lots of them simultaneously.

The basics
ETFs often sport lower expense ratios than their mutual-fund cousins. This ETF, focused on international telecom stocks, sports a relatively low expense ratio -- an annual fee -- of 0.5%. It recently yielded about 2.8% and is fairly small, so if you're thinking of buying, beware of possibly large spreads between its bid and ask prices. Consider using a limit order if you want to buy in.

This international telecom stocks ETF topped the world market's performance over the past three years but lagged it over the past five. As with most investments, of course, we can't expect outstanding performances in every quarter or year. Investors with conviction need to wait for their holdings to deliver.

Why international telecom stocks?
Investors should seek international diversification, lest a major U.S. downswing devastate your portfolio. International telecom stocks are appealing because the telecommunications industry is dynamic and growing, and many of its denizens offer tasty dividends, too.

More than a handful of international telecom stocks had solid performances over the past year. Vodafone (VOD 1.10%) surged 53%, for example, yielding 2.8%. The U.K.-based telecom titan offers a handy way to profit from Europe's rebounding economy, and it's making further investments in Europe as well. Vodafone is setting its sights further, too, recently winning approval to buy all of its Indian subsidiary (it currently owns 64% of it) and positioning itself to benefit more from India's growth. Bears don't like Vodafone's shrinking free cash flow, but bulls like its hefty dividend. There's speculation that AT&T might buy Vodafone. Vodafone's first half of fiscal 2014 offered revenue and operating income slightly above expectations.

Nippon Telegraph and Telephone (NYSE: NTT) jumped 28%, yielding about 3%. The company has a 50% market share in Japan's wireline telecommunications. It's not a cash cow on its own, but its NTT DoCoMo subsidiary is a noteworthy contributor to its performance, with a dominant position in Japan's wireless arena. In a November conference call, management noted two key business strategies of Nippon Telegraph and Telephone: expansion of global cloud service and a strengthening of network service competitiveness.

Telefonica SA (TEF 0.97%), which is also known as Telef, gained 18%, and its recently reinstated dividend yields about 5.7%. The Spanish telecom concern serves Europe, which is recovering from economic troubles, and Latin America, which offers a brisker growth rate than Europe. Telefonica is saddled with a lot of debt, though, in part from its investments in Latin America, which will take time to deliver results. Telefonica has shuttered some of its offerings, such as its U.S.-based voice-over-IP service Jajah and its free messaging service, Tu Me. It also sold its Czech-based subsidiary for $3.3 billion. Some see  Telefonica as a possible acquisition target or merger candidate.

Orange (ORAN 1.27%) advanced 17% and yields 4.3%. Formerly known as France Telecom, it has been shedding some non-core assets and focusing on some faster-growing ones. (Its operations in Africa and the Middle East, for example, are promising.) Orange has a lot of debt, but is working on paying that down. Analysts at Zacks Equity Research recently upgraded the stock to outperform, liking its 4G expansion and improved market position. Some balk at Orange's steep P/E ratio and growing competition in France, but bulls like the international telecom stock's solid cash flow and emerging market potential -- not to mention its dividend.

The big picture
If you're interested in adding some international telecom stocks to your portfolio, consider doing so via an ETF. A well-chosen ETF can grant you instant diversification across any industry or group of companies -- and make investing in it and profiting from it that much easier.