* Q4 net EPS $0.24 vs Wall St view $0.34

* Q4 sales $85.8 mln vs year-ago $111.9 mln

* No financial outlook, cites economy

* Shares fall 9.7 pct after-hours (Recasts with estimates, adds CEO comment, background)

NEW YORK, Feb 18 (Reuters) - Blue Nile Inc (NILE.O) posted a lower quarterly profit that missed expectations as sales fell, and said the economic downturn prevented it from giving a financial outlook, sending its shares down 9.7 percent.

Jewelry retailers like Blue Nile, and others such as Zale Corp (ZLC.N), Finlay Enterprises (FNLY.OB) and Tiffany & Co (TIF.N), took a big hit to holiday revenue, as consumers sought discounts and cut spending on anything that was discretionary.

Blue Nile Chief Executive Diane Irvine said "our business was impacted by the pullback in consumer spending in this weak economic climate."

The online jewelry retailer's net profit fell to $3.5 million, or 24 cents a share, in the fourth quarter ended Jan. 4, from $7.5 million, or 45 cents a share, a year earlier.

Analysts, on average, expected it to earn 34 cents a share, according to Reuters Estimates.

Sales at the Seattle-based company fell to $85.8 million from $111.9 million a year earlier.

Blue Nile said it bought back $1.2 million worth of its shares during the quarter.

"Given the uncertainty surrounding the economic environment and consumer spending, we are not providing financial guidance at this time," Chief Financial Officer Marc Stolzman said in a statement.

The company is among many that have blamed the weak economy for their inability to provide an outlook for sales or profit.

Shares of Blue Nile fell 9.7 percent to $19.00 after closing on the Nasdaq at $21.03. (Reporting by Aarthi Sivaraman; Editing by Gary Hill and Matthew Lewis)