UPDATE 1-Pioneer Natural to sell shale stake to Sinochem for $1.7 bln

* To sell 40 percent of interest in Texas field

Sinochem to pay $500 mln in cash, rest in future drilling costs

* Pioneer shares rise 3 pct in premarket

Jan 30 (Reuters) - Oil and gas producer Pioneer Natural Resources Co said it would sell a 40 percent interest in the Wolfcamp shale field in Texas to China's state-run Sinochem Group Co Ltd for $1.7 billion.

The deal is the latest in a string of investments by Chinese companies in North America. State-controlled Chinese firms are seeking new energy sources to power the country's booming economy and gain understanding of emerging drilling methods to tap shale reserves at home.

Sinochem will pay $500 million in cash and will fund a portion of Pioneer's share of drilling and other costs.

Sinochem's businesses span energy, agriculture, chemicals, real estate and financial services, and the company has 200 units including Sinochem International Corp, Sinofert Holdings Ltd and Franshion Properties (China) Ltd.

Under the agreement, Sinochem will acquire about 82,800 net acres of leasehold.

Pioneer will continue as the operator of the joint interest area and conduct all leasing, drilling and marketing activities, the company said.

Production in the joint interest area averaged about 2,000 barrels oil equivalent per day in 2012.

Pioneer and Sinochem plan to drill 86 horizontal wells this year in Wolfcamp, increasing it to 120 in 2014 and 165 in 2015.

The emerging Wolfcamp Shale may ultimately rival the success of Eagle Ford shale in the same state, information provider IHS Inc said in December.

Pioneer said it has discontinued efforts to sell its properties in the Barnett shale in north Texas. The fields had a carrying value $456.8 million as of Dec. 31, 2011.

Shares of Pioneer rose 3 percent before the bell to $121 on Wednesday, after closing at $117.37 on the New York Stock Exchange on Tuesday.