UPDATE 1-SSE reiterates full year guidance

* H1 pretax profit 410.5 mln stg vs 303 mln

* Reiterates guidance for single-digit increase for FY

(Adds details)

LONDON, Nov 11 (Reuters) - British utility Scottish & Southern Energy (SSE.L) posted a 36 percent rise in first-half profit thanks to more favourable supply margins and maintained guidance for a modest increase in full-year profits.

The company, which is the second-largest electricity generator across the UK and Ireland, also said it will submit plans to develop the UK's biggest carbon dioxide capture trial facility at its Ferrybridge coal-fired power station in Yorkshire.

The company, which was hit last year by high wholesale prices for gas and electricity and low availability of some of its power stations, posted adjusted first-half profit of 410.5 million pounds ($683.9 million). The forecast was for adjusted pretax profit of 424 million pounds, up from 303 million pounds last year, according to a poll of 6 analysts supplied by the company.

German energy giant E.ON (EONGn.DE) also reported third-quarter results on Wednesday and revised upwards its outlook for 2009. [ID:nL0728161]

SSE's pretax profit for the year to end-March is estimated to come in at 1.29 billion pounds, up from 1.25 billion last year, according to a survey by Thomson Reuters I/B/E/S.

"Our financial performance in the first six months is consistent with our goal of a moderate, single digit increase in adjusted profit before tax for the financial year as a whole," the company said in a statement.

Its shares closed on Tuesday at 1,080 pence, giving it a market cap of 9.98 billion pounds. ($1=.6002 Pound) (Reporting by Victoria Bryan; Editing by Joel Dimmock)