KIEV — Investors in the $500 million eurobond of Ukraine's Naftogaz have agreed to swap the debt for a new issue with a higher coupon payment, the state energy firm said on Monday.

The company, often at the center of energy rows with Russia and battered by higher gas import prices, wants to change the terms of all its foreign debt through the issue of new debt worth $1.65 billion with coupon payments of 9.5 percent. 
The eurobond had a coupon of 8.125 percent.

"More than 93 percent of the existing notes voted in favor of the consent solicitation, and, accordingly, the extraordinary resolution put to noteholders at the noteholder meeting was passed," Naftogaz said in a statement.

Rating agencies said Naftogaz was in restricted default after it failed to repay the bond by a Sept. 30 deadline. It had paid out the coupon.

Naftogaz had previously said 92 percent of the bondholders had agreed to the restructuring. The bondholders' deadline to decide on the new terms passed on Friday, and on Monday the investors met to vote on the restructuring.

The company is concurrently holding talks with its bilateral creditors. Local agencies have said these include Credit Suisse's loan of about $550 million, Deutsche Bank's $395 million and Depha's $220 million.

"Negotiations with the bilateral lenders to Naftogaz are progressing, and Naftogaz is encouraged by the continued constructive nature of these discussions," the company said.