* FTSE 100 index rises 0.4 percent
* Market bets on more strong U.S. jobs data
* Vodafone gains boosted by EC green light on Ono
By Francesco Canepa
LONDON, July 3 (Reuters) - Britain's top share index climbed to a three-week high on Thursday anticipating that U.S. non-farm payrolls numbers, due later in the session, will reinforce belief the world's largest economy is gaining momentum.
The blue-chip FTSE 100 index has been trading in a range of about 200 points since May, compared with a band of about 450 points in the first four months of 2014. The index was up 28.41 points, 0.4 percent, at 6,844.78 points by 0949 GMT, after hitting the highest level since mid-June at 6,846.72 points.
The FTSE 100 is less than 2 percent away from its peak of 6,950.60, set in late 1999, and investors have been waiting for catalysts to lift it out of a trading range - such as stronger economic data and corporate earnings or a pick-up in the pace of mergers and acquisitions.
Better-than-expected U.S. private-sector data on Wednesday raised expectations that the official non-farm payroll numbers will also beat forecasts. Forecasts gathered by Reuters centred on 212,000 jobs being added in June.
"The U.S. labour market data has been quite healthy recently and it should reinforce confidence about the strength and breadth of the U.S. recovery. It should be good for equities," Daniel McCormack, strategist with Macquarie, said.
"We may set new highs after the summer, but it largely depends on two things - earnings and corporate activity. If M&A (merger and acquisition) continues, then that would be a powerful support for the market."
Investors will also look for the European Central Bank to provide some details of its new stimulus measures after its meeting later in the day.
Heavyweight Vodafone was the top contributor to the FTSE's advance as it rose 1.4 percent after the European Commission approved the company's 7.2 billion-euro ($9.8 billion) acquisition of Spain's largest cable operator, Ono, without conditions.
Miner Antofagasta surged 4 percent to the top of the FTSE as copper climbed to its highest in more than four months and investors welcomed further details on the company's plans to combine two of its mines in Chile to cut costs.
"This is the first time that they have provided some additional detail on some of the cost initiatives that they are implementing," Alon Olsha, an analyst at Macquarie Research, said. "The market is clearly encouraged by it."
Antofagasta's shares were testing the upper end of a trading range that has trapped the stock since late April in volume already almost equal to its full-day average for the past three months.
Charts suggested gains for the broader market. Bill McNamara, technical analyst at Charles Stanley, said that the FTSE 100's close on Wednesday above its 50-day moving average raised expectations the move higher might run a bit further.
He said the next area of potential resistance was seen at around 6,840 points, and if the index exceeded that level, it would be in a strong position to test this year's highs at around 6,880 points. (Additional reporting by Atul Prakash; Editing by Ruth Pitchford)