S.Africa's rand firmer vs dlr, metals lift bourse

* Rand firmer against broadly weaker dollar

* Stocks rebound on higher metal prices, bargain-hunting

* Supply worries weigh on govt bonds

JOHANNESBURG, Oct 5 (Reuters) - South Africa's rand firmed against the dollar Monday as the greenback weakened and rallying global markets encouraged bets on high-risk assets while a bounce in metal prices also lifted the local bourse.

The rand ZAR=D3 was trading at 7.58 against the dollar at 142 GMT, 0.85 percent firmer than Friday's New York close of 7.6450.

"It looks likes there's buyers for the rand ... on the back of equities or the carry trade. Definitely, global buyers are still a lot more positive on the rand in the short term," said a Johannesburg-based dealer.

"I think 7.55/52 are levels to watch on the downside and 7.75 the cap on the topside."

The rand broke through the 7.50 mark last week after a potential tie-up with local mobile operator MTN (MTNJ.J) and India's Bharti Airtel (BRTI.BO) fell through. It touched a 1-month low of 7.79/dlr on Friday.

The Johannesburg Top-40 index .JTOPI gained 0.64 percent to 22,062.56 points, while the broader All-Share index JALSH advanced 0.58 percent to 24,661.53 points.

"I think we have seen a rebound in the resource stocks after being hammered last week and generally the world markets are just picking up after their lows," said Desmond Reilly, a trader at PSG Online Securities.

"So there's a bit of bargain hunting coming into the market this week," he said.

The JSE platinum sector .JPLAT was up 4.29 percent as spot platinum XPT= was firmer than Friday's close, trading at $1281.50 an ounce at 1523 GMT.

Impala Platinum (IMPJ.J) led the entire bourse with a 5.22 percent climb to 170.99 rand, followed by Anglo Platinum (AMSJ.J) which added 3.14 percent to 660.10 rand.

Other gainers were RMB Holdings (RMHJ.J), which rose 3.05 percent to 26.99 rand and media giant Naspers (NPNJn.J), which tacked on 2.58 percent to 254 rand.

After gaining more than 5 percent last week, MTN started the week on a weaker footing, losing 2.17 percent to 128.75.

"I think after the hype of that MTN/Bharti deal falling at the end of last week there was a bit of buying, so you might just find a bit of profit-taking," Garth Mackenzie, a trader at Imara SP Reid said.

South African government bonds weakened, with the yield on the 2015 bond ZAR157= up 4.5 basis points to 8.335 percent and that on the 2036 note ZAR209= 3.5 basis points higher at 8.455 percent.

Worries about increased supply of government paper on the market are on investor minds as South Africa faces a wider fiscal deficit due to the country's first recession since 1992.

This week's government bond auction on Tuesday sees the government increase the amount on offer to 2 billion rand from the usual 1.8 billion rand previously. (Reporting by Phumza Macanda and Phakamisa Ndzamela; Editing by Andy Bruce)