The Hamburg-based company, which had filed for insolvency in 2013, said in March that it would file for an IPO in the next two years.

"Going public is contingent on being larger," Chief Executive Andrew de Pass told Reuters on Tuesday.

Conergy is looking to buy a large, regional solar company or another private company with a global presence, said de Pass, who took over as CEO in March.

"For long-term success, we need size and scale. Therefore, my focus as CEO in 2015 is to conclude one or two consolidating M&A transactions, for which we are currently in discussions with a number of parties."

De Pass previously worked at Kawa Capital Management and led the Miami-based asset manager's efforts to buy Conergy's solar projects business, and the company brand name, when it went bankrupt in 2013.

Conergy, like several other solar companies, had been hurt by reduced consumer subsidies in Germany and a plunge in solar equipment prices due to a worldwide supply glut.

The rest of the old company was broken up and sold in pieces to buyers including Robert Bosch GMBH [ROBG.UL].

Kawa holds a majority stake in the new Conergy. RWE, Germany's second-biggest utility, bought a minority interest in March.

Conergy develops solar plants and has about 1 gigawatt (GW) of installed capacity in countries including the United States and United Kingdom.

De Pass said Conergy expects to build another 700 megawatt of projects in the near future and wants to double that capacity through these acquisitions.

Conergy expects revenue of $600 million-$700 million (387 million-451 million) in 2015, de Pass said. The company had said earlier that it expected revenue of $700 million this year, up more than 40 percent from 2014.

(Editing by Sayantani Ghosh and Joyjeet Das in Bengaluru)

By Swetha Gopinath