HONG KONG, April 30 (Reuters) - HSBC Holdings reported a 1.8% drop in first-quarter profit on Tuesday as it struggles to cope with rising costs from expansion in Asia and amid inflationary pressures.

Pretax profit came in at $12.7 billion for the quarter ended March versus $12.9 billion a year earlier.

The results were better than the $12.6 billion average of analysts' forecasts compiled by HSBC.

The London-headquartered bank also announced $3 billion worth of share buybacks on top of $2 billion in share purchases announced in February. (Reporting by Selena Li in Kong Kong and Lawrence White in London; Editing by Edwina Gibbs)