* SGN stake sale could fetch around 1 billion pounds -
Jefferies
* SSE reports 3.3 pct fall in full-year adjusted pre-tax
profit
* SSE loses 370,000 customer accounts in year to end March
(Updates throughout)
By Karolin Schaps
LONDON, May 18 (Reuters) - Britain's second-biggest energy
supplier, SSE SSE.L , is considering selling up to a third of
its 50 percent stake in regional gas distribution business SGN
to raise cash for shareholders or to reinvest, it said on
Wednesday.
The plan to sell down its interest in SGN, the operator of
two regional gas networks, in Scotland and southern England,
follows a similar move by National Grid NG.L , which is seeking
to sell a majority stake in its own 8.5 billion-pound ($12.3
billion) UK gas networks business.
SSE could raise around 1 billion pounds ($1.4 billion) from
its sale, based on a 20 percent premium to the regulated asset
base value of SGN, analysts at Jefferies said. SGN is co-owned
by two Canadian pension fund investors, Ontario Teachers'
Pension Plan and Borealis BINTR.UL .
SSE also reported on Wednesday a 3.3 percent fall in
full-year adjusted pre-tax profits to 1.5 billion pounds ($2.16
billion) after making hefty impairment charges on the value of
its coal and gas-fired power plants as well as its gas
production business due to weak energy prices.
Like its biggest rival, Centrica CNA.L , SSE has lost many
customers in its retail business mainly to smaller and often
cheaper suppliers who now control 15.4 percent of the dual
gas-electricity fuel market, up from just 1 percent four years
ago.
SSE's total customer accounts in Britain and Ireland fell to
8.21 million at the end of March, 370,000 accounts lower than
the same time last year. In comparison, Centrica's British Gas
lost 119,000 accounts in its 2015 financial year and another
224,000 over the course of the first three months of 2016.
The utility raised its dividend for the year by 1.1 percent
to 89.4 pence per share, in line with expectations, and pledged
to keep dividend increases at least in line with the UK's Retail
Price Index (RPI) rate of inflation in 2016/17 and beyond.
However, Jefferies analysts said the dividend could be under
threat if British power prices do not rise from current levels.
"Even a modest move up in prices to the 45-50 pounds per MWh
range would alleviate much of the pressure," they said.
"But if that doesn't happen, then SSE's ability to maintain
investment at this rate and its dividend will be called into
question."
Shares in SSE were down 0.6 percent at 1,537 pence by 0827
GMT.
($1 = 0.6924 pounds)
(Editing by Greg Mahlich)