* FTSE 100 up 0.3 percent
* Miners drive strongest gains
* Smurfit rises as U.S. rival drops bid
* RPC looking to sell assets, stock tumbles (Updates prices, adds details, quotes)
By Danilo Masoni and Helen Reid
MILAN/LONDON, June 6 (Reuters) - Gains among mining stocks on stronger metal prices helped British shares outperform a sluggish European equity market on Wednesday, while packaging firm RPC sold off sharply after updating investors on its spending plans.
The commodity-heavy FTSE 100 .FTSE index rose 0.3 percent and mid caps .FTMC climbed 0.6 percent. The pan-European STOXX 600 index .STOXX ended flat.
Miners provided the biggest uplift to the FTSE as base metal prices rose, with copper and lead gaining ground on prospects of a supply squeeze. American AAL.L , Rio Tinto RIO.L and Antofagasta ANTO.L all rose more than 3 percent, while BHP Billiton BLT.L gained 2.5 percent on reports the Anglo-Australian miner had received first bids for its U.S. shale business. mid-caps, RPC RPC.L tumbled 11.9 percent after the plastic packager announced an increase in investments to take advantage of strong demand in China. said the investment plans had dented the firm's cash flow figures.
"RPC saw organic growth, although in the face of rising prices and a currency tailwind we think free cash flow looks low," said Paul Moran, head of research for Northern Trust (NASDAQ:NTRS) Capital Markets.
WH Smith SMWH.L was a standout gainer, up 7.5 percent, following a well-received update.
"High Street total sales and LFL ... is a great performance in the context of a very challenging environment and will surprise" said Investec analysts.
Smurfit Kappa SKG.L , Europe's biggest packager, began the day at the top of the FTSE as investors warmed to its prospects after U.S. rival International Paper IP.N dropped plans to make an offer for the Ireland-based group. stock pared gains to end the session up just 0.5 percent, however.
"The fundamentals of the European packaging sector are in excellent shape," Davy analyst Barry Dixon said in a note, upgrading his earnings forecasts and price target for the stock.
"Smurfit is the leading player in this market and therefore the most exposed to the positive dynamics. This, combined with the deep intrinsic value of its assets, points to significant hidden value and upside in the share," he added.
Consumer staples were a weak spot with British American Tobacco BATS.L , Imperial Brands IMB.L and Unilever ULVR.L down 1 to 1.8 percent as the dollar .DXY fell.
Insurance stocks across Europe and the UK also fell following a report that U.S. Internet giant Amazon AMZN.O was considering extending its empire to offer home insurance. Line DLGD.L and Aviva AV.L dropped on the report, but recovered to trade only slightly lower by the end of the session.