UPDATE 2-Weak customer spending hurts Acme Packet outlook, shares fall

* Q4 adj EPS $0.26 vs est $0.28

* Q4 rev $83 mln vs $85.2 mln

* Sees FY12 adj EPS $0.96-$1.00 vs est $1.23

* Shrs fall 12 percent in after-mkt trade

FEB 2 (Reuters) - Network gear maker Acme Packet Inc reported fourth-quarter results below analysts' expectations and forecast a weak full-year profit as its customers scaled back on spending and delayed orders.

Acme Packet shares slid 12 percent to $27.17 in after-market trade on the Nasdaq.

The company forecast full-year 2012 adjusted earnings of 96 cents to $1 per share, below analysts' average expectations of $1.23 per share, according to Thomson Reuters I/B/E/S.

On a post-earnings call with analysts Acme Packet's Chief Executive Andrew Ory said it could not deliver on the expectations it had set for itself in 2011 due to underperformance in the North American service provider market.

"This reflects a slowdown in capex in the second half of the year and delays caused by consolidation activities among various service providers," Ory said.

Investors have wiped out almost a third of Acme Packet's market value since last October when the company flagged concerns about lower capital spending by its telecom customers such as AT&T and Verizon.

"We don't expect the North American CapEx environment to improve in the first half," Ory added.

The disappointing forecast has raised questions about the pace of Acme Packet's revenue growth this year and about its ability to manage its pipeline.

The company's outlook mirrors the bleak first-quarter forecasts given by its peers Juniper Networks and Riverbed Technologies last month.

The recent break up of a planned multi-billion dollar merger between AT&T and T-Mobile USA as well labor-related issues at Verizon have curbed technology spending, especially in the second half of 2011.

For the October-December period, the company, which makes network equipment that enhances data delivery across networks, earned $8.7 million, or 12 cents a share, compared with $14.5 million, or 25 cents a share, a year ago.