By Rodrigo Campos

NEW YORK (Reuters) - An index of stocks across the world ended flat on Monday while Wall Street dipped, and oil prices rose to a three-month high after Iran's leader called on non-OPEC producers to help support prices.

The U.S. dollar rose against a basket of its peers after strong manufacturing data, sterling brushed against a three-decade low versus the greenback and the Colombian peso fell after voters rejected a peace deal to end a more than 50-year-old war.

Traders were on the lookout for news from Deutsche Bank, which is working to reach a settlement with U.S. authorities who have demanded a fine of up to $14 billion for the way the bank sold toxic mortgage-backed securities.

The German stock market was closed on Monday but Deutsche's U.S.-listed shares <DB.N> fell as much as 3.7 percent. The stock ended down 0.8 percent at $12.98 after hitting last week $11.185, a record low.

"The feeling is there will be a negotiation lowering that penalty but it's certainly a bit of an overhang on the overall market," said Tim Ghriskey, chief investment officer of Solaris Group in Bedford Hills, New York.

The Dow Jones industrial average <.DJI> fell 54.3 points, or 0.3 percent, to 18,253.85, the S&P 500 <.SPX> lost 7.07 points, or 0.33 percent, to 2,161.2 and the Nasdaq Composite <.IXIC> dropped 11.13 points, or 0.21 percent, to 5,300.87.

The pan-European STOXX 600 index <.STOXX> ticked up less than 0.1 percent and the FTSEurofirst 300 index <.FTEU3> ended flat. MSCI's gauge of stocks across the globe <.MIWD00000PUS> dipped 0.05 percent.

Crude futures prices rose, taking Brent above $50 a barrel and U.S. crude to three-month highs after comments by Iran's leader exhorting the need for other oil producers to join OPEC in supporting the market.

"There's already a soft commitment from Russia that it will be part of the OPEC plan and if more non-OPEC members get on board, prices can only go higher," said Phil Flynn, analyst at the Price Futures Group brokerage in Chicago.

U.S. crude <CLc1> was up 0.9 percent at $48.66 a barrel and Brent <LCOc1> last traded at $50.81, up 1.2 percent on the day.

Sterling fell 1 percent against the dollar to its lowest since July, touching a low of $1.2815 <GBP=> and slightly above a 31-year low of $1.2796 after Britain on Sunday set a March deadline to start the process to leave the European Union. It also hit a three-year low against the euro of 87.47 pence per euro <EURGBP=>.

The Colombian peso <COP=> fell as much as 2.8 percent versus the dollar after voters rejected a hard-negotiated deal between the government and Marxist guerrillas to end a 52-year war. The currency ended down 1.65 percent.

The dollar index, which measures the greenback against a basket of six major currencies, gained on data showing the U.S. manufacturing sector grew by more than expected in September. The index <.DXY> was last up 0.3 percent.

The manufacturing data boosted expectations that the Federal Reserve would raise interest rates by December, sending U.S. Treasury yields higher.

Benchmark 10-year notes <US10YT=RR> fell 6/32 in price to yield 1.6256 percent, up from 1.606 percent on Friday.

Spot gold prices <XAU=> fell $3.80 or 0.3 percent, to $1,312 an ounce.

(Additional reporting by Richard Leong, Barani Krishnan, Noel Randewich and Karen Brettell; Editing by Meredith Mazzilli and Lisa Shumaker)