DryShips Inc said won a $1.1 billion deepwater drilling contract from Brazil's Petrobras, doubling its backlog to over $2 billion ahead of a planned IPO of the business in the next few months.

With the contract for the two rigs, the Greece-based dry cargo shipper and oil driller has secured contracts for all of its initial newbuilding drillships, CEO George Economou said in a statement accompanying the company's first-quarter results.

DryShips said it now planned to publicly list its drilling unit, Ocean Rig , in the United States in the next few months. Earlier, it said it expected to list in June.

With eight rig units, Ocean Rig now has become the largest pure player in the ultra deepwater sector, where companies increasing their spending.

"For DryShips the diversification in the drilling space is paying off at a particularly opportune time given the challenging drybulk and tanker markets," the company said.

First-quarter results were hurt by lower net voyage revenues as costs rose. "The bulk shipping markets remain challenging," DryShips said.

Capesizes, or the largest dry bulk vessels, barely managed to cover their running costs during the first quarter as demand was hit by flooding in Australia and the tsunami in Japan.

January-March net income rose to $25.8 million, or 7 cents per share, from $13.3 million, or 4 cents per share, a year earlier. Excluding items, the company earned 15 cents per share. Revenue rose 7 percent to $207.4 million.

Analysts had expected earnings of 16 cents per share on revenue of $234.1 million, according to Thomson Reuters I/B/E/S. (Reuters)