UPDATE 2-FTSE wraps best week in three years ahead of Christmas

* FTSE 100 up 0.1%, FTSE 250 up 0.04%
* Johnson wins vote on Brexit deal
* Carnival jumps on upbeat outlook
* Shell lower after Q4 update
* NMC Health has worst week ever

(Adds news items, analyst comment, updates to closing prices)
By Shashwat Awasthi and Yadarisa Shabong
Dec 20 (Reuters) - London's main index enjoyed its best
weekly performance since December 2016, as shares of exporters
continued to benefit from a pound that is subdued amid renewed
concerns about a chaotic Brexit at the end of 2020.
The FTSE 100 .FTSE inched 0.1% higher on Friday, also
clocking its longest winning streak since May 2017 and the FTSE
250 .FTMC managed to squeeze in a 0.04% gain as Prime Minister
Boris Johnson won approval for his Brexit deal.
After a breakthrough in U.S.-China trade talks and Johnson's
election victory this month, investors now drew solace from
Johnson's first step towards fulfilling his campaign pledge to
deliver Brexit by Jan. 31.
"The fact that the bill was successful might have been
reassuring to the pound – the faster things move, the more time
there might be to hash out a trade deal with the EU," said
Spreadex analyst Connor Campbell.
Lawmakers voted by 358 to 234 to pass the second reading of
the legislation, underlining Johnson's large majority in
parliament that should ensure a smooth ratification of the
divorce deal. Johnson's win triggered a rally in domestically-exposed
stocks, though worries about Brexit have re-emerged due to a new
provision for a hard, December 2020 deadline to reach a trade
agreement with the European Union.
Sterling hovered near two-week lows, helping exporter stocks
such as Diageo DGE.L , the world's largest spirits company, and
household goods maker Reckitt Benckiser RB.L .
A weaker pound against the dollar helps international
companies boost their earnings numbers.
Despite swinging between sharp gains and losses this week,
the midcaps, whose components earn most of their money
domestically, still bagged an eighth successive weekly jump.
London-listed shares of Carnival CCL.L climbed 6.8%,
topping the blue-chip index after the cruise operator forecast
2020 profit above Wall Street expectations. Shell RDSa.L dipped 1.6%, the biggest drag on the FTSE
100, after expecting to write down up to $2.3 billion in the
fourth quarter and lowering its oil products sales
forecast. UAE-based NMC Health NMC.L , targeted by short seller Muddy
Waters, plunged another 15.4% on its worst week ever. Its stock
has shed nearly half of its value since Tuesday.
Shares of Just Eat JE.L fell 2.1%, a day after Dutch firms
Prosus NV PRX.AS and Takeaway.com TKWY.AS tabled their final
offers for the company. The British online food delivery company
backs Takeaway's offer.