NEW YORK (CNN/Money) - Britain's FTSE 100 index finished a volatile session firmly in the red Friday, sagging ahead of Monday's U.S. holiday, although pub operator Mitchells & Butlers gained after it shelved an expansion move.

Mitchells & Butlers topped the FTSE gainers' list with a 4.6 percent gain after it pulled out of a £2.3 billion bid process for the Scottish & Newcastle pub chain.

The FTSE 100 closed down 36.9 points at the day's low of 4,161.1, faltering after an early session peak of 4,227.7 as an erratic Wall Street reversed early losses in response to a mixed bag of economic data only to give up fragile gains later.

Elsewhere in Europe, the Swiss SMI was off 1.5 percent, and France's CAC 40 was 0.4 percent weaker. Germany's DAX ended 0.1 percent softer.

In London, Martin Evans, head of global research at Etrade, did not attach much importance to the FTSE's second straight close below 4,200 after last week's advance to within sight of 4,300.

"At this stage in the cycle and the economic recovery and equity market recovery, emotive levels of indices are not that significant. The fact that we're below 4,200 is not an issue for us. If anything, fund managers will be using it as an opportunity to buy into stocks," Evans said.

NatWest Stockbrokers Head Dealer Martin Dobson said he saw the FTSE 100 pinned in a narrow range for the next five to six weeks as investors wait for the next burst of company results.

"A lot of people are waiting for the third-quarter results to see what direction this market is going to take. We really do need stronger growth and you're not going to see that over the summer months," Dobson said.

Insurance company Royal & Sun Alliance was a big FTSE loser, down 4 percent on a fresh burst of speculation that it might disclose a rights issue, possibly with next Thursday's half-year results. The company declined to comment.

Shares of J. Sainsbury, Britain's second-biggest supermarket, fell 2.2 percent after "till roll" sales data from market research company Taylor Nelson Sofres showed a sales dip of around 2 percent for Sainsbury in the 12 weeks ended Aug. 17, from the same period last year.  

-- Reuters contributed to the story