Britain's FTSE posts fourth week of gains, travel stocks fall after Nice attack

* FTSE 100 index up 0.2 percent at close

* Travel & Leisure stocks among top losers

* FTSE 100 posts 4th straight week of gains (Recasts, adds detail and quote, updates prices at close)

By Kit Rees and Atul Prakash

LONDON, July 15 (Reuters) - Britain's top share index edged higher on Friday, though travel-related stocks fell after an attack in the French city of Nice (Milan: NICE.MI - news) that killed more than 80 people.

The blue-chip FTSE 100 index was lower for most of the trading session before breaking a three-day losing streak to end the day 0.2 percent higher at 6,669.24 points.

Travel and leisure companies were hit hard following the Nice attack, where a gunman at the wheel of a heavy truck ploughed into a crowd celebrating Bastille Day in Nice late on Thursday, killing at least 84 people and injuring scores more in what President Francois Hollande called a terrorist act.

Budget airline easyJet was the biggest faller, down 2.6 percent, joined by cruise company Carnival (LSE: CCL.L - news) , which fell 2.3 percent. TUI (LSE: 0NLA.L - news) and IAG were also down 1.1 percent and 0.9 percent respectively.

The FTSE was also subdued on the first session after the Paris attacks in November but gained 3.5 percent over the following week as the market refocused on fundamentals.

The index's late rally was broad-based, allowing it to post its fourth straight week of gains.

"More defensive sectors have led the way, showing that safety and yield still come top of the list when stock-picking," Chris Beauchamp, senior market analyst at IG (LSE: IGG.L - news) , said in a note.

The benchmark FTSE 100 index is up around 5 percent since the Brexit vote in June in sterling terms, but down 6.7 percent in U.S (Other OTC: UBGXF - news) . dollar terms due to a sharp decline in the British currency.

"Many traders are of the opinion that stocks, especially in Europe, have still plenty of catching up to do especially considering that markets in the U.S. are at new all-time highs," Markus Huber, trader at City of London Markets, said. (Reporting by Atul Prakash; Editing by Susan Fenton and Jane Merriman)