Top share index rose on Friday in erratic trade due to futures and options expiries, attempting to break free from key technical resistance with the help of Royal Bank of Scotland which led a sector rally on the back of a broker upgrade.

London's blue chip index <.FTSE> was up 30.58 points, or 0.5 percent at 5,971.30 by 11.51 a.m., fighting to break out of a range that has largely been in place since early February.

Technical analysts at Trading central said the FTSE 100 was looking bullish but cautioned the blue chip index faced significant barriers around the 5,989 level.

The index has completed its pull-back to the rising 50-day moving average and has just pushed above February's highs, Nicolas Suiffet, analyst at Trading Central, said.

The configuration is positive and a continuation of the recovery remains the most probable scenario, he said.

Banks <.FTNMX8350> were the top performing sector led by Royal Bank of Scotland , up 4.3 percent after UBS upgraded its recommendation on the part state-owned lender to buy as a clear recovery play on Britain and the United States.

UBS raised its GDP estimates for 2012 and 2013.

A more positive view on the UK combined with improving economic momentum in the U.S. where growth expectations are already well embedded will pave a way for improved performance in RBS's core business and should contribute to lower losses in the non-core division, the bank said in a note.

Citigroup were in bullish mood too, as the U.S. bank said the level of FTSE 100 index could double over the next 10 years.

Other financials rallied as the prospect of rising markets and lower volatility, a crude gauge of investor fear, boosted appetite for asset managers -- which hemorrhaged fund flows in 2011 in the face of wildly fluctuating markets -- and interdealer brokers.

Hargreaves Lansdown rose 3.4 percent, while ICAP added 2.3 percent.

SHIRE REBOUNDS

Shire gained 1.2 percent as JPMorgan Cazenove upgraded its recommendation on the firm to overweight from neutral on valuation grounds, helping the drugmaker pare losses made in the previous session.

JPMorgan said Shire trades on only 14.2 times 2013 estimated price earnings, which look too cheap for a 17 percent 2013-17 earnings per share compound annual growth rate.

Elsewhere, Tullow Oil jumped 4.1 percent after the London-listed company said an appraisal well in Ghana had successfully encountered oil in high quality reservoirs.

Tullow was the third-most heavily traded stock among UK blue chips on Friday, with volume at 116 percent of its 90-day daily average.

Overall market volumes remained lacklustre, suggesting many investors were unwilling to put fresh money into a rally that began in November when central banks flooded the market with cheap money in an effort to stave off another financial crisis.

It is difficult to see where the next positive catalyst might come from here while volumes remain so low, but certainly if U.S. economic data continues to improve as it has, that will certainly help things, said Richard Hunter, head of equities at Hargreaves Lansdown.

Investors have a number of further U.S. economic releases to digest on Friday, including consumer prices data and industrial output figures. U.S. futures pointed towards a higher open on Wall Street, which supported gains on the FTSE 100.

(Written by David Brett)