SYDNEY, March 20 (Reuters) - Australian investors will be showered in upwards of A$50 billion in cash over the next few weeks as dividend and bond payments come due, an injection of spending power that could prove a timely fillip for economic growth.

April looks like being a bumper month as a record A$27 billion in bonds mature, while coupon payments of A$4.3 billion amount to six times the monthly average.

The flood comes as corporates are scheduled to pay over A$21 billion in dividends, a peculiar feature of Australia where companies pay out two third of earnings - more than double the level of their U.S. counterparts.

The total flow equates to roughly 3.3 percentage points of the country's entire annual economic output and analysts are hopeful some of its will spill over into added spending.

"The redistribution of money from companies to consumers will put dollars in people's pockets and hopefully provide useful stimulus to the Australian economy," said Craig James, chief economist at CommSec.

"Hopefully some investors will put any extra dollars to work in retail therapy."

The economy could do with the help as growth slowed to a sub par 2.5 percent last year amid a fading mining boom and a widespread reluctance by businesses to invest.

Seeking to revive activity, the Reserve Bank of Australia (RBA) cut interest rates to an historic low of 2.25 percent in February and is widely expected to ease again in the next couple of months.

Still, it is far from clear how much of the cash windfall will end up in domestic consumption.

Indeed, a chunk is set to go abroad as foreigners owned roughly A$411 billion of Australian stocks at the end of last year, out of a total market of A$1.5 trillion.

BHP Billiton and Rio Tinto are first and third respectively on the list of top dividend payers in Australia, yet foreign investors own the majority of shares in both and will get the lion's share of the cash.

Much is also likely to go back into bonds or stocks. Dividend reinvestment plans have been increasingly popular in the last year with most major companies running them.

Banks have been especially keen as reinvestment helps build the equity buffers needed to meet tighter global capital standards.

(Reporting by Wayne Cole; Editing by Eric Meijer)