* Resources services firms under pressure

* Iron ore, oil prices have fallen sharply

* Shares down 35 pct (Recasts, adds company comments)

SYDNEY, Jan 28 (Reuters) - Australian mining products maker Bradken Ltd said private equity bidders Bain Capital and Pacific Equity Partners pulled a $730 million takeover proposal because of volatility in the commodities sector, sending its shares down by a third.

Bradken said in a statement on Wednesday that the would-be buyers had walked away citing difficulties in obtaining financing due to volatility in global commodity and money markets.

The proposal's collapse underscores the stress that companies which service the mining sector have come under since plunging commodities prices prompted many resources firms to cut spending.

Bradken shares fell 34 percent to A$2.70 by mid-session, compared with the A$5.10 proposal Bain and PEP made in December and the A$6.00 approach they made in August, just before plunging iron ore and oil prices sent Australia's mining sector into turmoil.

Since PEP, Australia's largest private equity firm, and United States-based Bain made their initial approach, the spot price of iron ore has dropped by a third and the spot price of crude oil has nearly halved.

Bradken said it would focus on profitable growth via purchases of foundries in India and its own cost cutting. But it noted "there are no visible signs at this stage of a turnaround in the mining cycle".

PEP is on the hunt for new targets since cashing in on several large Australian investments in 2014, including listing services firm Spotless Ltd and toilet paper maker Asaleo Care Ltd.

It also failed in a A$1 billion takeover approach for struggling compliance firm SAI Global Ltd.

(Reporting by Byron Kaye and Lincoln Feast; Editing by Stephen Coates)