Unocal Corp. said Thursday that first-quarter earnings jumped 69 percent from last year on strong crude oil and natural gas prices, and a 5 percent increase in output.

El Segundo-based Unocal reported net income of $454 million ($1.66 per diluted share) for the first quarter ended March 31, compared with $269 million ($1) for the like period a year earlier. Revenue rose to $2.2 billion from $1.9 billion in the year-ago period.

Analysts surveyed by Thomson Financial expected the company to post earnings of $1.37 per share on sales of $1.2 billion in the first quarter.

Excluding a $22 million gain from the sale of Unocal's interest in Hindustan Oil Exploration, which was offset partially by $11 million in provisions for environmental and litigation matters, Unocal earned $441 million ($1.62 per diluted share) in the latest quarter, versus $239 million (89 cents) for the like period a year earlier.

Unocal said first-quarter results reflected higher worldwide crude oil and natural gas prices, international production and natural gas storage margins, and lower exploration and interest expense. These positive factors were offset partially by lower North America natural gas production and higher administrative and general expense.

Unocal said oil and gas production in the first quarter averaged 429,000 barrels of oil equivalent (BOE) per day, an increase from the 409,000 BOE per day produced a year ago. The company cited higher liquids and natural gas production in Asia. Unocal said it currently expects worldwide average production for 2005 to exceed 430,000 BOE per day, up from a previous estimate of 425,000 BOE per day.