London -- Emerging market borrowers issued a record volume of bonds denominated in hard currency during 2014, seizing the opportunity of ultra-low interest rates though few expect the trend to carry on into 2015.

According to Thomson Reuters data, total issuance from emerging market borrowers, both sovereign and corporate, amounted to nearly $480 billion in 2014, across 742 deals, compared with $439 billion in 2013 and 725 deals.

The bulk of issuance this year came from companies, which sold $367 of bonds across 647 transactions, while sovereign borrowers issued $106 billion across 72 deals.

"It's not surprising. We are coming to the end of an ultra-low rate environment in the U.S. and credit spreads have been very low. The market's been wide open for issuers," said Michael Cirami, co-director and portfolio manager at Eaton Vance Investment Managers.

China was the biggest source of hard currency issuance this year, accounting for $101 billion of bonds across 137 deals, followed by Brazil with $44 billion and 45 issues, and Mexico with $36 billion and 42 issues.

However, with the U.S. Federal Reserve expected to start to raise rates at some point in the coming year, the cost of servicing dollar debt is expected to become more expensive and therefore less attractive for borrowers.

David Hauner, head of fixed income and economics for Emerging Europe, Middle East and Africa at Bank of America/Merrill Lynch expects dollar-denominated sovereign issuance to fall by around a quarter next year.

"Sovereign issuance in total as of end-November was $106 billion and for next year we forecast gross issuance of $75 billion, so quite a bit of decline," he said. "From an investor point of view it is actually helpful for the asset class."

The drop in sovereign issuance will be partly countered by relatively robust corporate issuance, estimated at around $350 billion, around half of which will come from "rapidly growing" Asian companies, BofA Merrill Lynch estimates.

It could be a case, however, of EM countries switching into one of the other major global currencies.