The FTSE 100 gained 0.1 percent, while the FTSE 250 <.FTMC> was roughly unchanged as the market wrapped up its final full week of trading in 2018.
Wall Street lifted the mood, rising in volatile trade on Friday after heavy losses on the chances of a partial U.S. government shutdown and of further interest rate increases by the Federal Reserve.
That guided a 0.6 percent gain in HSBC, which has a larger international presence, making it the top boost to the FTSE 100.
The blue chip index outperformed its European peers due to its exposure to the mining sector <.FTNMX1770>. Anglo American climbed 2.8 percent, while Rio Tinto, BHP and Antofagasta rose 1.4-1.6 percent on higher copper prices.
UK indices were still on track for their worst quarter since 2011, when Europe was battling a sovereign debt crisis, and their worst year since 2008 amid growing worries about slower global growth, Brexit and rising U.S. borrowing costs.
Vodafone dropped 2 percent and was among the biggest drags on the main index after a tender offer to replace PwC as its auditor.
However, investors developed an appetite for Just Eat as it rose 3 percent after rival Takeaway.com struck a 930-million-euro ($1.07 billion) deal to buy larger rival Delivery Hero activities in Germany.
The British takeaway group was urged to sell assets by a shareholder earlier this week, and analysts have since said that the calls raised the possibility of a takeover or go-private deal.
Royal Mail shares gained 1.5 percent before the firm leaves the blue-chip index as part of the reweightings on Dec. 24.
Nike's better-than-expected results provided temporary respite to the battered retail sector, with JD Sports jumping over 7 percent to be among the top mid-cap gainers.
"Nike results are a little ray of sunshine in the market," said Paul Mumford, a fund manager at Cavendish Asset Management.
Still, surveys showed that British consumers are at their gloomiest in more than five years with business sentiment at its weakest since the 2016 vote to leave the European Union.
"I think the main sentiment is going to come after the New Year when we start having retailers' trading statements coming through," said Mumford.
Elsewhere on the midcaps, RPC Group Plc, Europe's largest plastics packaging firm, erased earlier gains and closed the day with a 0.7 percent dip after it extended the deadline again for Apollo Global Management to make a firm offer to buy the company or walk away.
The deadline has been extended four times and Bain Capital earlier pulled out of the race without giving a reason.
"If I was an RPC shareholder, I would be anticipating the magic of Christmas more positively but as always with magic, there can/might be an element of illusion," said Peel Hunt analysts.
In small-caps, Interserve rose 3.3 percent after the support services group announced a rescue plan involving a debt-for-equity swap in an attempt to avoid a Carillion-style collapse.
The shares, which had rallied as much as 12 percent at the open, have still lost 88 percent year to date, reflecting the problems of the sector.
(Reporting by Muvija M and Shashwat Awasthi in Bengaluru; editing by Josephine Mason and David Stamp)
By Muvija M and Shashwat Awasthi