* Q4 loss
.80/shr vs EPS $1.41 year-ago
* Sees deepwater Gulf of Mexico production from March 2010
* Expects Q1 production of 1.5 mln mmboe
* Sees 2010 capex of $570 mln
* Shares up 12 pct (Recasts, adds conference call details, background, updates share movement)
BANGALORE, March 12 (Reuters) - ATP Oil & Gas Corp (ATPG.O) posted a fourth-quarter loss due to delays related to a well re-completion, but forecast a sequential increase in first quarter production volumes, sending its shares up 12 percent.
On a conference call, the company said it expects production of 1.5 million barrels of oil equivalents (mmboe) in the first quarter, 15 percent higher than the fourth quarter.
The company's deepwater Gulf of Mexico development, the Telemark Hub, is on schedule for first production later this month.
With the start of production at the Telemark Hub, ATP expects a further rise in its oil revenue as a percent of total revenue as well as its oil to gas production ratio during 2010.
The company also replaced 376 percent of its reserves, and it is based on additions of 22.0 mmboe, from all its sources, with independent third-party proved reserves of 135.2 mmboe for 2009.
Replacement rate is a measure of growth in production. A rate below 100 percent indicates a company is shrinking by finding fewer new fields to offset oil or gas it is pumping.
Oil and gas companies took advantage of new reserve reporting rules from the U.S Securities and Exchange Commission -- the first changes in 30 years -- providing more flexibility in allowing reserves to be reported.
The company's net loss attributable to shareholders for the quarter was $40.0 million, or 80 cents a share, compared with income of $50.2 million, or $1.41 a share, in the year-ago quarter.
Oil and gas revenue rose 53 percent to $74.3 million.
Analysts on an average were looking for loss of 12 cents a share, before items, on revenue of $77.0 million, according to Thomson Reuters I/B/E/S.
Oil and gas production for the quarter rose 44 percent to 1.3 mmboe.
Shares of the Houston-based company rose as much as 12 percent to $19.79, making them one of the top percentage gainers Friday on Nasdaq. The stock has risen more than 400 percent in the last one year. (Reporting by Arundhati Ramanathan in Bangalore; Editing by Ratul Ray Chaudhuri)