However, volume was low at 55 percent of the average 90 day volume, as many investors stayed out of the market after the U.S. Thanksgiving holiday ahead of a crucial meeting on Monday that will tackle the Greek debt crisis.

The International Monetary Fund has relaxed its debt-reduction target for Greece and only a 10 billion euro ($13 billion) gap remains to be filled before a vital aid instalment can be paid, Greece's finance minister said on Friday.

Volumes have been pretty lacklustre but there seems to be some optimism ahead of Monday and on a solution for the fiscal cliff, Atif Latif, Director of Trading at Guardian stockbrokers, said in an e-mail.

Also risk on has been apparent since the Chinese PMI data earlier this week and this has allowed miners to move back up on heavier volume, he said, referring to what he perceived to be a greater appetite for risky assets.

Although the short term outlook was better because of the U.S. holiday and a lack of economic data, he said traders remained concerned on the outcome for Europe and the low growth environment we are faced with.

The FTSE 100 index closed up 28.11 points, or 0.5 percent, at 5,819.14, taking gains for the week up to 3.8 percent, beating the year's best week so far, recorded in May.

It was only the third time this year the FTSE had posted five straight days of gains, with the U.S. Thanksgiving holiday on Thursday disrupting usual trends in Friday profit-taking activity.

The five consecutive day rally (in the UK market) is interesting, as the S&P has only ever rallied 4 consecutive days into Thanksgiving nine times before. And every time it's done that, it's rallied on the Friday as well, Andy Ash, Head of Sales at Monument Securities, said.

The S&P 500 was up 0.9 percent, with a strong opening in the United States helping to break the FTSE 100 through the 50 day moving average, though the rise could slow as the index approaches 5,921, the post-U.S. election high.

The pace at which it's coming back is difficult to stand in front of at these sort of levels, but as you get nearer the top of the range, the pace of the move will slow, Phil Roberts, chief European technical strategist at Barclays Capital, said.

The gains were broad based, with every sector contributing to the rise in the index. Miners rebounded from early falls to gain 0.3 percent, with Basic Materials adding 2.5 points to the index.

Xstrata and Glencore both rose 0.6 percent, after Xstrata said it had completed the construction of the first production line at its Koniambo project.

The news supported weekly gains in excess of 6.5 percent for both stocks after Glencore's protracted takeover of Xstrata was finally concluded and approved by EU regulators.

While energy and financials added a combined 11 points to the index, sectors perceived as defensive, such as tobacco, drugs and drinks groups, were also among top blue chip performers.