** Shares of oil refiner Delek US Holdings DK.N gain ~4% to $37.80
** DK posts surprise profit for the fourth quarter, helped by stronger performance in its refining segment
** Posts adjusted profit of 44 cents per share vs. analysts' average estimate of 76 cents loss per share - data compiled by LSEG
** Co posts a fourth-quarter profit of $78.3 million, compared with last year's loss of $413.8 million
** Co's refining segment posted an adjusted core profit of $314.1 million compared to a loss of $68.7 million a year ago
** Including session's move, stock up 27.4% YTD
(Reporting by Pranav Mathur in Bengaluru)
((Pranav.Mathur@thomsonreuters.com;))