Adds CEO quote, background, share price in paragraphs 3, 7-9

By Nerijus Adomaitis and Nora Buli

OSLO, June 16 (Reuters) - Norway's Equinor EQNR.OL said on Tuesday it will increase its share buybacks, returning more cash to owners as the war in the Middle East has boosted the price of oil and gas and sharply lifted the company's earnings.

Majority state-owned Equinor said in a strategy update it now plans to spend $3 billion on buying back its own shares this year, up from $1.5 billion projected in February before the U.S.-Israeli attack on Iran.

"Demand continues to grow and Equinor is uniquely positioned to provide reliable energy," CEO Anders Opedal said in a statement, adding that the company expected to deliver "superior returns" towards 2030.

The company aims to increase its oil and gas output by 150,000 barrels of oil equivalent per day (boed) by 2030 to a total of 2.3 million boed, it said.

Going forward the company plans to raise its quarterly cash dividend by 5% per year, it said.

Equinor plans annual share buybacks of between $2 billion and $4 billion from 2027, based on oil prices of $60 to $80 per barrel and European gas prices of $7 to $11 per million British thermal units (MMBtu), balance sheet strength, and the macro economic outlook, it said.

The group, which is 67% owned by the Norwegian government, is due give a strategy update to investors in New York later on Tuesday, marking the 25th anniversary of its 2001 listing on the New York Stock Exchange.

Equinor's second-quarter pretax profit, due to be released next month, is projected to almost double year-on-year to $12.3 billion, according to analysts polled by LSEG, which would make it the group's strongest result since the third quarter of 2022.

The company's share price soared after the outbreak of the Iran war on February 28 and is up 37% year-to-date even after giving up some gains in recent weeks on the prospect of a deal to end hostilities between Washington and Teheran.

On Tuesday the share traded down 0.4% by 1025 GMT lagging a European oil and gas index .SXEP which was up 0.6%.