SEOUL, April 8 (Reuters) - Samsung Electronics ( SSNLF ) on Tuesday estimated a 0.2% drop in first-quarter operating profit from a year earlier, beating analysts' estimates by far on solid smartphone sales and better-than-expected sales of memory chips.

Sales of conventional memory chips used in consumer electronic devices such as smartphones as well its AI chips likely came in better than expected, with some customers stockpiling chips ahead of potential U.S. tariffs on semiconductors, analysts said.

The world's largest memory chipmaker estimated an operating profit of 6.6 trillion won for the January-March period, versus a 5.1 trillion won LSEG SmartEstimate.

That would compare with 6.61 trillion won in the same period a year earlier and 6.49 trillion won in the preceding quarter.

Samsung is expected to release detailed results including a breakdown of earnings for each of its businesses in late April.

Analysts noted that Samsung's smartphone shipments rose in the first quarter, driven in part by preemptive shipments in certain channels, which they estimate were made in anticipation of the U.S. tariffs.

Last week, U.S. President Donald Trump announced a slew of reciprocal tariffs on trading partners, including China. While semiconductors were exempted from reciprocal tariffs, Trump on Thursday reiterated plans to levy tariffs on chips very soon.

South Korea's SK Hynix the world's second-largest memory chipmaker, said last month that some customers have brought forward orders in preparation for new U.S. tariffs, but was wary of a sustained demand recovery.

Micron Technology in March forecast third-quarter revenue above Wall Street estimates, signalling strong demand for its high-bandwidth memory (HBM) chips used in AI models.

(Reporting by Heekyong Yang and Joyce Lee and Hyunjoo Jin; Editing by Sonali Paul)