* Alma/Galia project production delayed to Q1 2014

* Sees 2013 output at lower end of guided range

* Shares fall 1.8 pct

(Recasts, adds CEO comment, share price)

By Sarah Young

LONDON, Aug 13 (Reuters) - Oil firm EnQuest ENQ.L strengthened its position in the North Sea with an acquisition, saying it sees growth in Britain's declining oil region even as it cautioned of a delay in its major Alma/Galia project.

Oil production from Alma/Galia would now begin in the first quarter of 2014 instead of later this year, said EnQuest, meaning its 2013 average production would come in at the lower end of guidance of 22,000 barrels of oil equivalent per day (boepd) to 27,000 boepd.

EnQuest, which specialises in extending the life of old oil fields, produces all of its oil in the North Sea. Its production will jump by around 60 percent when Alma/Galia comes onstream.

"We're only talking about a few months here...Nothing to worry investors. We'll have four of the wells ready rather than two, so I think the production will start off at a higher rate," EnQuest's chief executive Amjad Bseisu said in an interview.

EnQuest also on Tuesday bought a stake in the Avalon prospect in the North Sea, in a deal which will give it a 50 percent stake in a well. Enquest will pay part of drilling costs up to a limit of 12.5 million pounds.

The company said it saw growth opportunities in the North Sea but only up until a point, in a sign of the maturity of the area.

Britain launched a review of the North Sea earlier this year as it attempts to stem recent big falls in production from output which has been in decline since 1999. ID:nL5N0EM2BY

"We see ourselves getting to 50,000 barrels a day in the North Sea, growing beyond that is going to be difficult, that's why we're looking outside," Bseisu.

The company bought a foothold in Malaysia last year and has more recently moved into Tunisia. ID:nL3N0EA1HN

Shares in EnQuest slipped 1.8 percent with analysts citing disappointment at the longer time-frame for a project which will expand production by around 13,000 boepd.

"Positive changes at Kraken more than offset Alma/Galia delays," Numis analyst Sanjeev Bahl said, referring to another of EnQuest's oil projects, where it recently found more oil at Kraken North.

The company said that Kraken North would be treated as a separate field for tax purposes, potentially boosting its finances as it benefits from heavy-oil tax breaks worth an addition 800 million pounds ($1.24 billion).

Liberum analysts added that the results were mixed but the long-term growth story remained intact.

The Alma/Galia development, a revitalisation of Britain's first producing oil field, was taking longer than the company had expected due to the need for a more thorough refurbishment of the floating production storage and offloading vessel, it said. ID:nL5N0CQ1AT

The company posted a 13.2 percent drop in profit before tax and net finance costs to $167.2 million in the first half of the year versus the year-earlier period due to a lower realised oil price, higher depletion costs and a one-off cost at another field. ($1 = 0.6460 British pounds)

(Edited by Paul Sandle)

((sarah.young@thomsonreuters.com)(+44 20 7542 1109)(Reuters Messaging: sarah.young.thomsonreuters@reuters.net))

Keywords: ENQUEST RESULTS/