UPDATE 1-International drilling helps Halliburton beat estimates

* First-quarter profit $0.73 vs est. $0.71

* Revenue rises 5 pct to $7.35 billion

* Shares rise 1.6 pct before the bell

(Adds details from statement, background, estimates, shares)

April 21 (Reuters) - Halliburton Co, the world's No. 2 oilfield services company, reported better-than-expected quarterly results, helped by robust drilling activity in Russia, Saudi Arabia and Angola.

Halliburton, traditionally dominant in the United States, has been making a big push into international markets to combat weakness in North America.

Drilling activity in North America has fallen due to weak natural gas prices that have intensified competition among oilfield services providers for a smaller number of contracts.

Revenue and operating income increased 13 percent in the Middle East and Asia region in the first quarter ended March 31.

Revenue in Europe, Africa and the Commonwealth of Independent States (CIS) rose 9 percent, while operating income jumped 21 percent.

Halliburton shares were up 1.6 percent at $61.90 in trading before the bell. Up to Thursday's close, the stock gained 20 percent this year.

The company said operations in North America were hurt by lower prices for pressure pumping services, higher logistics costs and disruptions in drilling due to the harsh weather.

Rivals Schlumberger Ltd and Baker Hughes Inc also posted better-than-expected quarterly profits on Thursday.

Net income attributable to Halliburton was $622 million, or 73 cents per share, compared with a loss of $18 million, or 2 cents per share, a year earlier.

Analysts on average had expected earnings of 71 cents per share, according to Thomson Reuters I/B/E/S.

The year earlier quarter included a pre-tax charge of $1 billion related to the Gulf of Mexico spill in 2010.

Halliburton was a contractor for BP Plc, owner of the well that blew out causing the worst offshore oil spill in the United States.

Revenue rose about 5 percent to $7.35 billion, beating analysts' average estimate of $7.24 billion.

(Reporting by Swetha Gopinath in Bangalore; Editing by Sriraj Kalluvila)