Royal Dutch Shell has agreed to sell stakes in 10 North Sea oil fields to smaller rival Chrysaor for as much as $3.8 billion as it dumps assets to refocus its business in an era of lower oil prices.

Some 400 employees are expected to transfer to Chrysaor as part of the deal. The assets produced 115,000 barrels of oil equivalent a day last year, more than half the 211,000 barrels generated by Shell's North Sea operations.

Oil companies are cutting costs and selling assets to cope with a lower oil price environment.

Shell is facing additional pressure following its $54 billion takeover of BG Group PLC last year. That deal increased Shell's proven reserves by 25 percent, but critics questioned its logic following the drop in oil prices.