UPDATE 1-Sierra Leone passes mining bill, hikes royalties

* Sierra Leone passes new mining bill

* Act raises royalties, increases social contributions

* Gov't already looking at existing deals

* For related factbox click [ID:nLH355311] (Recasts, updates with passage of bill)

FREETOWN, Nov 17 (Reuters) - Sierra Leone's parliament has passed a new mining act that raises royalties and increases community benefits despite the opposition walking out, a senior minister said late on Tuesday.

The new Mines and Minerals Act 2009 will hike diamond and gold royalties, give the government the right to take a stake in big mining projects and require companies to contribute to local community funds.

The bill aims to remedy the effects of years of mismanagement, corruption and a 1991-2002 civil war that have hamstrung the West African nation's mining potential, leaving it among the world's poorest countries despite vast resources.

Passage came on the eve of the Sierra Leone Trade and Investment Forum in London, which the country hopes will attract a raft of interest in an economy still emerging from civil war.

"We got the bill through parliament," Minister of Minerals and Presidential Affairs Alpha Kanu told Reuters by telephone. "There was a lot of opposition because of a procedural issue but everyone liked the bill itself."