HOUSTON, Aug 11 (Reuters) - Chevron Corp last year proposed to acquire an at least 50% stake in Noble Energy's Eastern Mediterranean natural-gas fields, leading to July's all-stock deal, a proxy filing on Tuesday showed.

The proposed $5 billion deal would boost Chevron's U.S. shale oil holdings and give it vast natural gas holdings off the coast of Israel. Noble originally went looking for a partner to help finance its Leviathan gas project.

The purchase still faces a vote by Noble shareholders, who are expected to approve it. Chevron shares on Tuesday were off six cents apiece at $89.67 while Noble's lost four cents at $10.65. The proxy filing came after 4 p.m. (Reporting by Gary McWilliams Editing by Chris Reese)