Lafarge and Standard Chartered help European shares gain

* FTSEurofirst 300 up 0.4 pct after losing 0.7 pct on Tuesday

* Stronger Standard Chartered, Lafarge (Paris: FR0000120537 - news) help broader market

* Greek banks, auto stocks among top decliners

* Markets await Fed's policy statement, due at 1800 GMT

By Atul Prakash

LONDON, March 18 (Reuters) - European shares rose on Wednesday, with Standard Chartered (HKSE: 2888.HK - news) surging on broker upgrades and Lafarge leading the construction and materials sector higher on expectations that a merger deal with Holcim (Other OTC: HCMLF - news) could be saved.

Lafarge rose 5.7 percent after sources said the cement maker was seeking to save its merger with Switzerland's Holcim and the two were discussing on a new CEO for the combined group that would see current Lafarge boss Bruno Lafont in a different role.

Lafont was presented as the future CEO, but the Swiss side has grown dissatisfied with his leadership and threatened to walk away if the issue is not resolved, the people said.

"The two major hurdles in any deal like this are the price and the composition of the board. If they could agree on the chief executive for the combined group, then that would be a major step in the right direction," Philippe Gijsels, head of research at BNP Paribas Fortis Global Markets in Brussels, said.

The STOXX Europe 600 Construction and Materials index rose 1.2 percent, the top sectoral gainer, while the pan-European FTSEurofirst 300 index was up 0.4 percent at 1,589.91 points by 1520 GMT.

Standard Chartered, up 7.8 percent, led the FTSEurofirst 300 higher, after Bernstein double upgraded its stance on the stock to "outperform" and Barclays (LSE: BARC.L - news) upgraded to "overweight" from "equalweight".

However, gains were capped by weaker autos, with Germany's BMW (Swiss: BMW.SW - news) falling 3.6 percent after saying it expected 2015 sales volumes and profit before tax to rise by mid to high single-digit percentages, more subdued than its guidance a year ago.

The European automobile sector index fell 2.1 percent, with analysts saying that investors were also taking profits after the sector's 30 percent rally this year.

Greek banks fell 8.3 percent, dragged down by a 10 percent fall in National Bank (NYSE: NBHC - news) of Greece and an 8.6 percent slide in Alpha Bank (Other OTC: ALBWF - news) on concerns about the country's debt situation.

The European commissioner for economics, Pierre Moscovici, said Greece must stay in the euro zone, but only on the conditions agreed with euro zone finance ministers last month when it asked for an extension of its bailout.

"The awareness about the Greek debt situation has changed somewhat in the past two days," said Gerhard Schwarz, head of equity strategy at Baader Bank (Xetra: 508810 - news) in Munich. "A Greek exit (from the euro zone) would certainly undermine the ECB's statement that the euro is irreversible."

Investors were also cautious ahead of the Federal Reserve's policy statement, due after the end of the European session, for clues about when U.S. interest rates will rise.

Across Europe, Britain's FTSE 100 rose 1.3 percent, with oil and financial stocks up after changes announced in the UK government's budget, while Sweden's stock market was up 1.9 percent after hitting a record highs as the country's central bank cut its key repo rate and launched a new round of quantitative easing.

(Additional reporting by Blaise Robinson in Paris; Editing by Alison Williams)