The world's biggest fund manager has boosted its stake in Sky TV in a move a local analyst says is an example of the global forces driving the New Zealand sharemarket to record levels.

New York-based BlackRock, which has US$4.6 trillion ($6.4 trillion) in assets under management, has boosted its stake in the pay TV operator to 9.3 per cent from 8.3 per cent previously, according to a notice lodged with the NZX this morning.

Harbour Asset Management portfolio manager and analyst Shane Solly said buying by international investors, like BlackRock, had been "pushing the New Zealand market along".

With interest rates and bond yields at record low levels around the world, major funds are pouring capital into equity markets in order to generate income.


And the New Zealand sharemarket - whose benchmark index, the S&P/NZX 50, has gained 15.7 per cent this year - has a reputation as a solid source of dividends.

"There's just more capital chasing relative yield certainty," Solly said.

"We're seeing more of this globally and it's not going to go away in a hurry - if anything it could continue to grow."

The increase in BlackRock's Sky TV holding could also be seen as a vote of confidence in the pay TV firm's $5 billion merger with Vodafone New Zealand.

But Solly said the impending deal would not have entered into BlackRock's processes around lifting its stake.

The merger, which got the green light from investors last month, is expected to be completed by the end of this year but still requires Commerce Commission and Overseas Investment Office approval.

It involves Sky TV acquiring Vodafone NZ for $3.44 billion through the issue of new shares at $5.40 a piece and $1.25 billion in cash, giving Vodafone Europe a 51 per cent share in the combined group.

Sky TV shares recently traded at $5.02.