Jonathan David has left Banc of America Securities, where he was managing director and global head of high-grade bond sales, according to Tara Burke, a B of A spokeswoman. The circumstances of his departure could not be determined, and Burke declined further comment. A buy-side source says David was very loyal to his former supervisor Jim Kelligrew, who also recently left BofA, where he ran the bulk of its investment-grade business. David and Kelligrew reportedly joined B of A together from Lehman Brothers. David did not return a call to his mobile phone.