The European benchmark Brent crude increased modestly on Friday session narrowing the Brent-WTI spread from $8.33 in April to current level of $6.70 after a report unveiled that stockpiles at Cushing in Oklahoma slipped to 21.7 million barrels. Brent for delivery in July gained $0.09 to $110.06 per barrel on the London's ICE Futures Europe exchange.