NEW YORK (Reuters) - Online diamond jeweler Blue Nile Inc (NILE.O) reported a higher-than-expected quarterly profit and forecast a rise in sales for the holiday quarter, sending shares up nearly 2 percent in after-hours trading.

Blue Nile engagement ring

Despite uneven sales trends and low consumer confidence which Chief Executive Diane Irvine said had been a drag on sales during the third quarter, Blue Nile forecast a 3 to 12 percent rise in sales in its fourth quarter, which will include the Black Friday and Christmas holiday shopping periods.

Shares were up 77 cents in after-hours trading from a closing price of $45.50 on Thursday on Nasdaq.

Blue Nile said net third-quarter sales rose 0.8 percent to $67.5 million, with the strongest growth from jewelry not intended as an engagement gift.

The company reported net profit of $2.8 million, or 19 cents per share, for the quarter ended Oct. 3, up 7.7 percent from $2.6 million, or 17 cents per share, a year earlier.

Analysts on average expected earnings of 18 cents per share, according to Thomson Reuters I/B/E/S.

The online retailer also forecast quarterly earnings per share from 41 cents to 46 cents, compared with Wall Street forecasts of 43 cents.

Through the close on regular trading on Thursday, Blue Nile shares have fallen 30.5 percent this year.

(Reporting by Phil Wahba. Editing by Robert MacMillan)