* Q4 operating EBITDA up 6 pct to 1.01 bln Sfr
* Sees 2015 cement volumes growing everywhere except Europe
* Possibility of change to merger terms seen increasing (Adds details on progress of merger)
By Oliver Hirt and Georgina Prodhan
ZURICH/FRANKFURT, Feb 23 (Reuters) - Swiss cement maker Holcim said its merger with Lafarge was on track to complete in the first half of the year as it reported a 6 percent rise in fourth-quarter core operating profit on Monday, outpacing growth at its French peer.
Holcim's fourth-quarter operating profit (EBITDA) rose to 1.01 billion Swiss francs ($1.06 billion), helped by faster-than-expected cost-cutting and strong cement sales in North America, slightly above analysts' estimates.
Lafarge last week reported a 1 percent like-for-like decline in fourth-quarter operating EBITDA (earnings before interest, tax, depreciation and amortisation).
The merger, if approved, will create the world's biggest cement maker with $44 billion in sales. The companies hope it will help them cope better with overcapacity and sluggish demand that have dogged the construction industry since the 2008 economic crisis.
Analysts have seen a potential divergence in earnings outlooks between the two companies as opening the possibility of a renegotiation of the terms of the deal, which foresees each Lafarge share being swapped for one Holcim share.
"Holcim's results were broadly in line with consensus expectations and once again confirm the better shape of the Swiss company versus its designated merger partner Lafarge, questioning the exchange ratio for the merger," said Baader-Helvea analyst Patrick Appenzeller, who rates the stock "hold".
Holcim shares closed up 1.1 percent at 73.15 francs, while Lafarge shares closed up 1 percent at 66.44 euros - about 2 percent below the Holcim price.
Asked whether Holcim's strong results versus Lafarge could affect the exchange ratio, Chief Executive Bernard Fontana told Reuters: "There is no automatic adjustment."
A Swiss-based Lafarge spokesman said a change to the merger terms was not on the agenda.
The all-share deal still needs anti-trust clearance in five jurisdictions including India - Holcim's biggest single market - the United States and Canada.
A capital increase needed for the merger to go through also needs to be approved by two-thirds of Holcim shareholders at a meeting expected to take place in late May or early June.
Holcim will shortly go on a road show to persuade investors of the value of the deal.
Harris Associates, Holcim's third-biggest institutional shareholder, declined to comment. Another top 10 investor who asked not to be named said it still backed the deal and was "fully supportive" of the share exchange.
Holcim reported a 2 percent increase in fourth-quarter net sales to 4.87 billion francs driven by stronger prices in North America, Europe and Asia-Pacific that outweighed lower volume sales in Europe, Latin America, Africa and the Middle East.
It said the franc's appreciation against the Indian rupee, the Indonesian rupee, the Canadian dollar and a number of Latin American currencies cost it 1.03 billion francs in net sales and 147 million francs in operating profit in 2014.
Holcim said cement volumes should rise in all regions except Europe this year, helping operating profit to rise to between 2.7 and 2.9 billion francs from 2.47 billion in 2014, with operating margins rising thanks to higher pricing and cost cuts.
It said it would pay a flat dividend of 1.30 francs per share, below expectations but in line with its policy of distributing one-third of net income.
Free cash flow fell 15 percent to 1.76 billion francs in 2014, Holcim said.
$1 = 0.9495 Swiss francs Additional reporting by Simon Jessop in London; Writing by Georgina Prodhan; Editing by Thomas Atkins, Jane Merriman and David Evans