The blue-chip FTSE 100 index was up 0.5 percent at 6,955.85 points going into the close of the trading session, near a record high of 6,974.26 set earlier this month.
Traders added that European equities were further supported by confirmation that the European Central Bank (ECB) will start a bond-buying programme -- aimed at boosting the region's economy -- this month, while the Bank of England also kept interest rates at record lows.
"I think that a new record of 7,000 points for the FTSE is just around the corner," said Berkeley Futures' associate director Richard Griffiths.
Insurer Aviva rose 6 percent, the top gainer in the FTSE 100, after reporting higher profits.
"The results are both broadly pleasing and in stark contrast to the travails of recent years, most notably the financial crisis and subsequent dividend cut in 2013," said Richard Hunter, head of equities at Hargreaves Lansdown stockbrokers, commenting on Aviva's results.
Rival insurer Friends Life also advanced 5.7 percent after reporting a 38 percent rise in operating profit before tax.
Shares in broadcaster ITV rose 3.2 percent after HSBC, Goldman Sachs, Berenberg, JPMorgan, Nomura and Exane all raised their price targets for the stock, a day after it announced the return of cash to shareholders. Goldman also added ITV to its "conviction list".
However, miners faced some selling pressure after China, the world's biggest metals consumer, lowered its economic growth target for 2015 to around 7.0 percent after 7.5 percent in 2014. The FTSE 350 Mining Index underperformed the broader market rally to trade flat.
British bank HSBC also fell 2.6 percent as it went "ex-dividend", meaning the stock was trading without the attraction of its latest dividend.
(Additional reporting by Atul Prakash; Editing by Toby Chopra)
By Sudip Kar-Gupta