The FTSE 100 was flat as a stronger pound placed pressure on relative value of the overseas earnings which dominate the FTSE 100.
Sterling was higher thanks to encouraging UK services data.
The index moved 1.7 points higher to 7,672 around midday.
Business activity growth across the UK service sector helped Markit's Purchasing Managers' Index rise from 53.8 in November to 54.2 in December.
Struggling department store Debenhams (DEB) disappointed the market after like-for-like sales fell in 1.3% in the 17 weeks to 30 December 2017. The company revealed that pre-tax profit for this year will now be between £55m and £65m, causing the shares to crash 16.8% to 29.6p.
Brent crude oil dipped 0.2% to $67.71 per barrel.
Wall Street was supported by an oil price rally overnight and strong US manufacturing data. The S&P 500 closed 0.6% higher at 2,713.
MID AND LARGE CAP RISERS AND FALLERS
In UK equities, healthcare provider NMC Health (NMC) acquired the outstanding minority stakes in Fakih IVF and As Salama Hospital for $218m, providing the shares with a 4.1% boost to £30.40.
SMALL CAP RISERS AND FALLERS
Engineering group Costain (COST) reported that full year results will meet the board's expectations, helping the shares tick 1.5% higher to 471.9p.
Digital marketer Be Heard (BHRD) shed 23% to 2.1p on a profit warning due to 'unexpected factors.' The firm said profitability for the year to 31 December was expected to fall below market expectations.
There was also bad news from tech specialist Ethernity Networks (ENET) as amendments to contracts is expected to negatively impact sales and profits for 2017. The stock plummeted 37.3% to 80.6p.
Shares in tech firm Sopheon (SPE) sparked 19.9% to 434p, driven by expectations that sales and pre-tax profits would beat previous guidance.
Radio networks business CyanConnode (CYAN) reported a 'significant' customer delayed a contract, which would hit revenue and drag it below anticipated levels. Shares in CyanConnode slumped 8% to 18.5p.