By Anusha Shrivastava Of DOW JONES NEWSWIRES NEW YORK -(Dow Jones)- Nabors Industries Ltd.'s (NBR) $700 million bond has launched and is scheduled to price later Thursday. The 10-year bond, rated Baa2, BBB/BBB+, was increased in size from an original $500 million. It launched at 235 basis points over Treasurys. It is one of more than $15 billion in new high-grade bonds that surfaced on Wednesday, as issuers sought to capitalize on low interest rates and eager investors. On Tuesday, corporate borrowers marketed more than $15 billion of debt, according to data provider Dealogic. That was the third-highest day for U.S.-marketed investment-grade bonds this year and the highest daily volume since Feb. 4, it said. Other issuers included Hewlett-Packard Co. (HPQ), American Express Credit Corp. and the Republic of Italy. -By Anusha Shrivastava, Dow Jones Newswires; 212-416-2227; anusha.shrivastava@dowjones.com