From The Washington Post:

The board of Unocal Corp. accepted a sweetened takeover offer from Chevron Corp. early Wednesday, dealing a setback to the politically sensitive, unsolicited bid for Unocal from Chinese oil company Cnooc Ltd.

In a bid anticipated by Unocal shareholders, Chevron offered $63.01 per share, or about $17 billion. Chevron initially offered about $16.5 billion.