SEOUL, July 31 (Reuters) - Samsung Electronics ( SSNLF )

reported on Thursday a 55% drop in second-quarter

operating profit as delays in high-bandwidth memory chip

shipments and U.S. export curbs on advanced chip sales to China

continued to drag on its key semiconductor division.

The world's largest memory chip maker posted 4.7 trillion

won ($3.37 billion) in operating profit for the April-June

period.

The result was in line with its earlier estimate of 4.6

trillion won, which had disappointed investors.