DOW JONES NEWSWIRES Noble Energy Inc. (NBL) reached a 15-year deal valued at $18 billion to supply Israel Electric Corp. with natural gas from reserves in a recent offshore discovery. The deal entitles Israel Electric to buy 2.7 trillion cubic feet of natural gas with an option to expand the amount to 3.5 Tcf. That would boost the estimated size of the deal to $23 billion, though actual revenue from the deal will depend on prices at the time of sale and other factors. The agreement is the latest step in Noble Energy's efforts to develop the Tamar field off Israel's coast. The company has touted a string of recent successes in the area known as the greater Levant basin, which is off the coasts of Cyprus, Israel, Lebanon and Syria. Recent discoveries in the basin leave the area poised to become a major natural-gas exporter, transforming the energy market in the region. Noble Energy's shares were recently up 8 cents at $98.30 after hours. The stock has climbed 11% over the past three months. -By Drew FitzGerald, Dow Jones Newswires; 212-416-2909; Andrew.FitzGerald@dowjones.com