UPDATE 1-Sealy posts Q2 net loss on charges

* Posts Q2 loss of 6 cents/shr

* Q2 sales fall 26 pct

* International sales fall 35 pct

* Sees market conditions remaining challenging

* Shares down about 7 pct

June 30 (Reuters) - Sealy Corp (ZZ.N), the world's largest mattress maker, posted a second-quarter net loss primarily due to the refinancing of some debt, but was also hurt by falling sales -- especially at its international segment.

Sealy and other mattress makers have been struggling with softer sales at its U.S. markets after cash-strapped shoppers cut down on their appetite for big-ticket items amid falling home values and tighter lending conditions.

But the company, whose brands include Sealy, Sealy Posturepedic, Stearns & Foster, had recently warned that domestic net sales have stabilized.

Sealy reported a 26 percent fall in overall sales to $298.5 million, with domestic sales falling 14 percent to $222.5 million and international sales falling 35 percent to $76.0 million.

Sealy, whose rivals include Tempur-Pedic International Inc (TPX.N) and Select Comfort Corp (SCSS.O), reported a net loss of $5.2 million, or 6 cents a share, compared with a profit of $12 million, or 13 cents a share, a year earlier.

The latest second quarter included a charge of 13 cents a share related to refinancing of its senior credit facility and rights for convertible notes.

Analysts on average had expected the company to earn 8 cents, before items, on revenue of $297.8 million, according to Reuters Estimates.

Sealy, whose largest shareholder is buyout firm Kohlberg Kravis Roberts & Co, has seen its stock fall nearly 64 percent in the last 12 months.

The Trinity, North Carolina-based company's stock was trading down 7 percent at $1.82 after the bell, after having closed at $1.96 Tuesday on the New York Stock Exchange. (Reporting by Vidya Lakshmi in Bangalore)