By Chuck Mikolajczak

NEW YORK (Reuters) – U.S. stock index futures edged lower on Tuesday, after the Dow and S&P marched to new record highs and the Nasdaq topped the 5,000 mark for the first time in 15 years.

* The Nasdaq <.IXIC> notched its first close above the milestone 5,000 mark since March 10, 2000, buoyed by a flurry of merger activity, for only the third close above that level in the history of the index. The Dow <.DJI> and S&P <.SPX> closed at their latest records as economic data pointed to a slowly improving economy.

* Investors will look to monthly auto sales data throughout the session for signs on the health of the U.S. economy and the appetite of consumer spending. Fiat Chrysler Automobiles’s <FCHA.MI> CEO said Volkswagen <VOWG_p.DE> is not the ideal candidate for a merger, adding he was exploring various M&A options.

* Electronics retailer Best Buy <BBY.N> climbed 4.8 percent to $ 40.50 in premarket trade after it reported quarterly results, announced a special dividend and the resumption of its share repurchase plan.

* Citigroup <C.N> gained 1 percent to $ 54 before the opening bell after it agreed to sell its consumer finance unit OneMain Financial Holdings Inc to subprime lender Springleaf Holdings Inc <LEAF.N> for $ 4.25 billion in cash.

* MannKind Corp <MNKD.O> tumbled 7.5 percent to $ 6.14 in premarket after Goldman Sachs cut its rating on the stock to “sell” from “neutral” and slashed its price target to $ 3 from $ 6 per share.

* European stock markets pulled back from earlier gains spurred by better-than-expected German retail sales data and merger speculation in the Portuguese banking sector, but remained near multi-year highs set in the prior session.

* Japan’s Nikkei stock average <.N225> erased early gains and ended 0.1 percent lower to snap a three-day winning streak, after the yen rebounded from a three-week low against the greenback touched earlier in the session. China stocks tumbled as investor excitement over a weekend interest rate cut waned.

Futures snapshot at 7:28 a.m. EST:

* S&P 500 e-minis <ESc1> were down 2.75 points, or 0.13 percent, with 71,440 contracts changing hands.

* Nasdaq 100 e-minis <NQc1> were down 3.75 points, or 0.08 percent, in volume of 8,213 contracts.

* Dow e-minis <1YMc1> were down 17 points, or 0.09 percent, with 9,905 contracts changing hands.

(Reporting by Chuck Mikolajczak; Editing by Chizu Nomiyama)