The FTSE 100 remained in positive territory despite a rise in the value of sterling against the dollar on media reports that a breakthrough on Brexit negotiations could emerge by the end of today.
A stronger pound impacts the relative value of the overseas earnings which dominate the index of leading UK shares.
The FTSE was up 0.5% at 7,338 after the US Senate approved corporate tax cuts over the weekend, providing companies with significant US sales with an uplift in their shares.
Among these were building materials business CRH (CRH), Carnival (CCL) and equipment hire company Ashtead (AHT), which gained up to 3.5%.
The merger of energy firms SSE (SSE) and Npower could be investigated by the Competition and Market Authority, but this left investors unfazed as SSE was flat £13.37.
Brent crude oil fell 1.4% to $62.81 per barrel. Gold declined 0.4% to $1,272 per ounce and copper was stable at $3.06 per pound.
On Wall Street, investors celebrated the Senate's approval of tax cuts as the Dow Jones rallied 1% to 24,478 around 4:40pm UK time.
The Nasdaq fell 0.3% to 6,825 as the market was unsure of the potential benefit for big tech firms.
MID AND LARGE CAP RISERS AND FALLERS
Hungarian airline Wizz Air (WIZZ) flew 2.4% higher to £35.39 on media reports over the weekend of its expansion plans, including a tripling in size of the airline's fleet of planes over the next nine years.
Shares in coach operator National Express (NEX) were up 1.4% at 370p on strong trading in autumn and an encouraging start to Christmas trading. It also announced new acquisitions in both Spain and the US to further expand its markets.
Miner Rio Tinto (RIO) appointed current non-executive director Simon Thompson as chairman from 5 March, who will take over from Jan du Plessis. The news caused the share price to move 1.1% higher to £35.41.
SMALL CAP RISERS AND FALLERS
In the pharmaceutical space, Circassia (CIR) reported successful results from its Phase IV study on its Tudorza chronic obstructive pulmonary disease treatment, but the stock failed to rise at 100.2p.
Biopharma company PureTech Health (PRTC) said affiliate Akili Interactive Labs reported positive results from its study in paediatric attention-deficit/hyperactivity disorder, causing the shares to jump 8.8% to 139.7p.
Motor retailer Pendragon (PDG) unveiled a strategy update, including the commencement of its sale process for its US division for £100m. An extra £100m could be gained from Pendragon scaling back its new car business in the UK, focusing on used cars and the resumption of its share buyback programme. Shares in the company accelerated 3% to 26p.
On AIM, life sciences firm TyraTech (TYR) catapulted 81.8% to 2.5p on plans to focus on its animal health products and the sale of its human lice treatment Vamousse to Alliance Pharma (APH) for $13m. According to the company, approximately $8.5m of the funds will be returned to shareholders.
Engineering group Versarien (VRS) signed an agreement with a global chemical supplier, which will allow both companies to collaborate across several projects, causing the shares to soar 32.2% to 80p.
Marketing services business Communisis (CMS) appointed Steve Rawlins to chief financial officer and to the company's board of directors, although a lack of updates on trading expectations weighed on the stock. Shares in Communisis dipped 2.4% to 60.5p.