FOREX-Pound rebounds from 23-yr lows vs dollar on G7 news

                                
 * News that G7 will address currency weakness boosts pound
                                
 * Euro rises in late trading
                                
 * Dollar falls vs yen as FX options expire
                                
 * S&P downgrades Portugal's credit rating
 (Recasts, adds details and quotes, changes byline)
                                
 By Vivianne Rodrigues
                                
 NEW YORK, Jan 21 (Reuters) - The British pound rebounded
from a 23-year low against the dollar on Wednesday after a
source told Reuters that its slide will be discussed at the
next meeting of the Group of Seven industrialized countries.
                                
 The pound, which had been driven down on fears about the UK
banking sector, was also helped by a late afternoon rally on
Wall Street. The equities gains also lifted the euro more than
1 percent against the dollar as safe-haven flows into the U.S.
currency slowed.
                                
 The pound has been under steady pressure this week as a
government rescue package for struggling British banks failed
to reassure investors or stem losses in banking stocks. At one
point on Wednesday, sterling fell to $1.3622, its lowest level
since 1985.
                                
 The declines came after shares of Barclays Plc <BARC.L>
tumbled by as much as a third in value to a 24-year low in
London on the threat it needs to raise funds or could be
nationalized. Barclays pared losses to close down 9.3 percent.
Shares in rival Lloyds Banking Group also fell sharply. For
details, see [ID:nLL283101]
                                
 "We are seeing the end of a financial bubble in the UK that
has lasted for about four or five years," said Roger Kubarych,
chief U.S. economist at Unicredit Markets and Investment
Banking in New York. "The pound and every other asset in the UK
was extremely overvalued. Now, it's all coming down."
                                
 Still, the pound rallied against the dollar and trimmed
losses versus the euro in late trade after a source said
sterling weakness will be discussed at the next G7 meeting in
February. For details, see [ID:nLL70613].
                                
 The G7 news cane after France's economy minister, Christine
Lagarde, said the Bank of England should take more steps to
support sterling. [ID:nLL742265]
                                
 Sterling was last 0.5 percent higher at $1.3973 <GBP=>
after moving in a $1.3622-$1.4021 range on the day. The euro
trimmed gains to 92.99 pence <EURGBP=>, after hitting intra-day
lows at 92.56 pence.
                                
 Elsewhere, the dollar fell to 87.10 yen, according to EBS,
its lowest level against the Japanese currency since 1995,
before recovering some ground amid the late afternoon rally on
Wall Street. It last traded at 89.40 <JPY=>, down 0.4 percent.
                                
 The greenback was initially driven lower by rising risk
aversion and a flurry of dollar/yen options that expired
without being exercised, leading options holders to sell the
U.S. currency.
                                
 The euro fell as low as 112.08 yen <EURJPY=>, a near
seven-year low, before recovering to 116.66 yen, up 0.8
percent. Against the dollar, it was last up 1.2 percent at
$1.3040 <EUR=>.
                                
 "The moves have been quite dramatic so it's not entirely
surprising to see a bit of a correction here," says Vassili
Serebriakov, currency strategist at Wells Fargo in New York.
                                
 INTERVENTION ON THE RADAR
                                
 The rapid gains in the yen raised speculation Japanese
authorities may intervene to stem the rise in the currency.
                                
 "At this pace, soon the yen may hit levels that will bring
some 'verbal' intervention back to the market," said Todd
Elmer, a currency strategist at Citigroup in New York.
                                
 The Swiss National Bank, meanwhile, said it may use
unlimited foreign exchange intervention to weaken the Swiss
franc and avert deflation.[ID:nZAT008113]. That pushed the euro
and dollar higher against the franc, with the dollar touching
$1.1615 francs <CHF=>, its highest level since early December.
                                
 Also in Europe, Portugal became the latest euro-zone
economy this year to be hit by a rating downgrade by Standard &
Poor's, following Greece and Spain [ID:nLL738555].
                                
 Analysts said that could continue to weigh on the euro.
                                
 "While the U.S. economy is obviously in a bad state, the
euro zone economy is in a much, much worse-case scenario than
the U.S.," said Matt Esteve, a foreign exchange trader at
Tempus Consulting in Washington. "The downgrading of Portugal
is just evidence of that."
 (Additional reporting by Steve C. Johnson, Wanfeng Zhou,
Gertrude Chavez-Dreyfuss and Nick Olivari; Editing by Leslie
Adler)