Shares of Diamond Offshore Drilling (DO) - Get Report tumbled 3.6% to $11 Monday even though the offshore oil and gas drilling contractor reported a narrower-than-expected first-quarter loss.

The Houston-based company reported a loss of $73.3 million, or 53 cents a share, compared with a profit of $19.3 million, or 14 cents a share, a year ago. Analysts were expecting the company to report a loss of 59 cents a share. Revenue totaled $233.5 million, beating Wall Street expectations of $232.9 million.

"We had a solid start to the year with fleet-wide operational efficiency of 97% and zero recordable incidents for the first quarter," Marc Edwards, president and CEO, said in a statement. "We are pleased to announce that we secured over four years of additional work across two of our drillships, the Ocean BlackRhino and Ocean BlackHawk, with Woodside in Senegal. These new contracts are a testament to our differentiated strategy of focusing on innovation to drive efficiency in offshore drilling."

Edwards also added that the "Ocean GreatWhite commenced the drilling of its first well during the quarter and we recently secured a new contract for the rig with a leading U.K. operator, which will directly follow the current Siccar Point Energy contract."

"We were also able to secure a new award for the Ocean Apex with BP in Australia, which will commence following the Woodside campaign," he said.