* Mining sub-index hits highest since April 2011

* All major sub-indexes in positive territory

* Westpac to sell Pacific businesses for $312 mln

Dec 7 (Reuters) - Australian shares on Monday hit their highest in more than nine months, as heavyweight miners scaled multi-year peaks riding on an iron ore rally that saw prices of the steelmaking ingredient leap to record highs last week.

Also helping the Australian benchmark start the week on a positive note was Wall Street's performance in the previous session, which saw indexes hit an all-time high as slowing U.S. job growth spurred stimulus bets.

Extending gains to a fifth session, the S&P/ASX 200 index rose up to 1.21%, its highest since Feb. 27.

Metcash was the top percentage gainer in the index, after the wholesaler reported a jump in its half-year earnings.

Also among top gainers, Downer EDI climbed to its highest since early March, on reports that it was considering a sale of its Open Cut Mining West Business to Maca Ltd.

All major sub-indexes were trading in positive territory.

Mining stocks hit their highest in nearly 10 years, as supply concerns and demand in China pushed iron ore prices to a record high on Friday.

Shares of Fortescue Metals Group hit a record high, while BHP Group and Rio Tinto touched their highest since April 2011 and May 2008, respectively.

Energy stocks gained up to 2.2%, with Santos rising 3.6% after inking a deal to supply liquefied natural gas from Barossa to Mitsubishi's unit.

Financials and gold stocks were up as much as 0.8% and 1.1%, respectively.

Westpac said it would sell its Pacific businesses for $312 million. Its shares rose as much as 1% to a one-week high.

In New Zealand, the benchmark added 0.6% by 1205 GMT, and was at 12,708.6 points.

Shares of Tilt Renewables were at a record high after its top shareholder Infratil said it was considering a sale of its stake in the company, which may result in an offer for all of Tilt. (Reporting by Arundhati Dutta in Bengaluru, Editing by Sherry Jacob-Phillips)