BHP Billiton weighs spin-off of unloved assets

* BHP says considering range of options, no decision made

* No timeframe for spin-off or sale decision

* Momentum builds for spin-off to shareholders - newspaper (Adds BHP, investor comments, industry context)

By Sonali Paul

MELBOURNE, April 1 (Reuters) - BHP Billiton (NYSE: BBL - news) is weighing a range of options to simplify its portfolio of assets, including a possible spin-off of unwanted businesses such as aluminium and nickel into a separate company, the top global miner said on Tuesday.

"We continue to actively study the next phase of simplification, including structural options, but will only pursue options that maximise value for BHP Billiton shareholders," the company said in a statement.

Chief Executive Andrew Mackenzie has said over the past year that the company plans to focus on its large iron ore, copper, coal and petroleum businesses, while selling off smaller, less profitable operations.

The company's statement on Tuesday came shortly after The Australian Financial Review newspaper reported that BHP was considering spinning off non-core assets into a separate company, offering shares to existing shareholders.

BHP shares rose as much as 2.2 percent to a three-week high after the report. They last traded up 1.7 percent at A$37.10 in a weaker broader market.

Spinning off a company with non-core assets would allow BHP to pare down at a time when it may be difficult to find buyers willing to pay a good price. It could also help flush out a buyer.

"It's a good bartering tool," said Tim Schroeders, a portfolio manager at Pengana Capital, which owns BHP shares.

"If you're going to go down the trade sale route, you can say, 'Yes, we'd like to get (these assets) off our books, but we do have this alternative in our back pocket. So if you're a buyer you need to come to the party.'"

The newspaper said BHP's "project river" review, with advice from Goldman Sachs (NYSE: GS-PB - news) , has been running for more than a year. Work has "gathered momentum", according to the report, with senior executives "leaning towards spinning off the company with potential listings on the Australian, London and South African stock exchanges."

It said findings of the study could be put to the BHP board at its meetings in April or May.

BHP said it is still running a detailed review of a range of alternatives. It gave no timeframe for a decision.

"We're looking at all the options," BHP spokeswoman Emily Perry said when asked whether options included a spin-off of the aluminium, nickel and bauxite businesses, which do not fit with its four biggest units - iron ore, copper, coal and petroleum businesses.

"By increasing our focus on these four pillars, with potash as a potential fifth, we will be able to more quickly improve the productivity and performance of our largest businesses," BHP said in its statement.

The company, however, is not looking to simplify its dual-listed structure, as its Australian and London stock exchange listings have worked well, Perry said.

BHP has already sold some petroleum, copper, coal, mineral sands and uranium assets and its diamonds business over the past few years, including $6.5 billion worth of sales announced or completed last year.

It has not spun off an asset to shareholders since 2002, when it spun out its flat steel products business as BlueScope Steel. That followed the spin-off of its OneSteel business, now Arrium (Frankfurt: ONL.F - news) , in 2000.

(Reporting by Sonali Paul; Editing by Richard Pullin and Kenneth Maxwell)