One of the most attractive emerging-market plays these days can be found in a country you might not suspect: the U.S.

Taking advantage of lower borrowing costs, companies from nations such as Brazil, Russia and Indonesia are piling into the U.S. debt market at a record pace, and the big beneficiaries may be investors, say advisers. Emerging-market firms issued a record $75 billion in dollar-denominated bonds in the first quarter, a 40% jump over the same period last year, according to Dealogic, a research firm.

That fresh supply gives investors a way to secure yields that are significantly higher than what is available in comparable bonds issued at home, portfolio managers say. The payout on the J.P. Morgan (JPM) Corporate Emerging Market Bond Index Broad Diversified, which has an average triple-B credit rating, currently averages 5.6%, or 1.1 percentage points above that of similarly rated U.S. corporate bonds.

Many fund managers are grabbing what they can. Sabur Moini, manager of the $1.1 billion Payden High Income fund (PYHRX), recently upped the fund's allocation to emerging-market corporate debt to 5%, from just 1% in August. Meg McClellan, U.S. head of fixed income for J.P. Morgan Private Bank, also is incorporating such bondsinto some clients' portfolios while "yields are still relatively high," she says.

But with the newfound interest, those yields aren't likely to stay so high for long, analysts say. Though the rush of corporate bond offerings has shown little sign of waning, neither has investor appetite. Chasing those plump yields, investors poured $14 billion into emerging-markets bond funds in the first quarter, the most since the third quarter of 2010, according to fund tracker EPFR Global.

Even with the big supply, money managers are snapping up bonds so quickly that yields are starting to feel the pressure. Yields on emerging-market corporate bonds, for instance, have slid 1.5 percentage points since October, according to J.P. Morgan data.

Of course, the fat payouts of emerging-market bonds are fat for a reason: Investors are taking more risk when they choose a bond from Russia over one issued by a company in the U.S., where accounting rules and practices are considered much stronger. Also, because the market for emerging-market corporate debt has taken off only in the last few years, investors have a short history for evaluating the performance of such bonds compared with their U.S. counterparts, says Blaise Antin, a managing director in the TCW Emerging Markets Group.

Still, any genuine risks are partly offset by the potential reward, advisers say. Developing countries are expected to expand 5.75% through 2013, nearly four times the growth projected for advanced economies, the International Monetary Fund says.

The growing supply of dollar-denominated foreign bonds also may appeal to investors reluctant to expose themselves to foreign currencies, which can add volatility to a portfolio, says Alexander Kozhemiakin, team leader for emerging markets for Standish.

To take advantage of the new issues, Mr. Kozhemiakin is swapping sovereign bonds, which tend to be issued in local currencies, for emerging-market corporate bonds in the $63 million Dreyfus Total Emerging Markets fund (DTMAX).

It is a double benefit, he says. "You are achieving issuer and country diversification."