Britain's FTSE falls to 2-1/2 week low, hit by banks and tech

* FTSE 100 (NasdaqGS: Z - news) down 2.1 pct

* Growth-sensitive stocks hit

* ARM falls on sector concerns

* Randgold rallies on results (Recasts, adds details, quote)

By Alistair Smout and Kit Rees

LONDON, Feb 8 (Reuters) - Britain's top share index fell on Monday to its lowest level in more than two weeks, weighed down by falls in banking stocks to multi-year lows, and weakness in the tech sector.

Growth sensitive sectors weighed on the FTSE 100 as concern over the state of the global economy mounted.

Financial stocks took more than 35 points off the FTSE 100, with the consumer discretionary sector and energy shares combining to take off nearly another 30 points.

Traders said concerns over bank margins in a negative interest rate environment were hurting the bank sector after central banks in Europe and Japan delivered dovish messages in January. Worries over a possible British vote to leave the European Union later this year were also weighing.

Emerging market exposed lender HSBC dropped to its lowest level since 2009.

"The banks have continued to have a weak start to the year on concerns (over) dividend cuts and weaker EM growth ... We (also) see some concerns on the outlook for Brexit if it occurs," said Atif Latif, director of trading at Guardian Stockbrokers, noting that swings in oil prices also had a big effect on the commodity-heavy FTSE.

After a steadier start, oil prices fell on Monday, with oil and gas stocks hit as U.S (Other OTC: UBGXF - news) . crude dipped below $30 a barrel.

The FTSE 100 index fell 123.32 points, or 2.1 percent to 5,724.74 points by 1440 GMT, slightly outperforming the European market. The index has already lost around 6 percent this month, and dropped to its lowest level since Jan. 21.

"This is a down-trending market so, for the time being, that 5900.00 level for the FTSE -- we seem to be leaving it behind us now," said Brenda Kelly, head analyst at London Capital Group.

Chip maker ARM Holdings (LSE: ARM.L - news) was down 5 percent, as Friday's big fall in the U.S. tech sector on continued.

Several brokers reiterated their "neutral" ratings for ARM ahead of its full-year earnings release on Wednesday.

Concerns regarding a slowdown in the U.S. tech sector after Apple (LSE: 0R2V.L - news) forecast its first revenue drop in 13 years at the end of January have hit shares of ARM Holdings, whose technology powers Apple's iPhone.

One of only seven gainers, precious metals miner Randgold Resources rose 8.2 percent following a strong set of full-year earnings.

The company said its full-year profit from mining fell by 11 percent, a better-than-expected result given the continued decline in gold prices. The stock is up around 30 percent this year as investors flocked to safe-haven investments

"RRS is one of the few companies to still generate earnings growth, while its investment discipline has left it well placed to withstand the current environment," analysts at Investec (Other OTC: ITCFY - news) said in a note.