South Korean tech giant Samsung Electronics today guided for weaker than expected second quarter earnings.

This comes as a supply shortage plagued its latest smartphone launch and tepid demand from key markets likely undercut sales. 

The guidance suggests that Samsung will struggle to replicate the explosive growth it recorded at the turn of the decade as smartphone competition intensifies and demand softens in China and Europe. 

Operating profit for the second quarter likely fell 4% from a year earlier to 6.9 trillion won ($6.13 billion), Samsung said in a filing.

This was its best profit performance in four quarters but also the seventh period of annual decline in a row. 

The average forecast from a Thomson Reuters survey of 39 analysts was a profit of 7.2 trillion won. 

Revenue for the quarter would fall 8.3% from a year earlier to 48 trillion won, well below the 53.4 trillion won average analyst forecast and the fifth consecutive quarter of annual decline. 

The company gave no other specifics and is expected to report its full results in late July. 

Samsung's annual profit is expected to rebound this year from a three-year low in 2014, but its shares have languished in recent months amid doubts about sales of its new Galaxy S6 smartphones. 

A failure to make enough curved-screen S6 edge models to meet demand likely hurt mobile-related earnings, analysts believe. 

While the company says it has fixed the problem, it may be too late to fully capitalise on a lull in competition for new high-end devices ahead of the launch of the latest Apple iPhones, expected as early as September. 

China's economic slowdown is also pinching smartphone makers' earnings. 

Chinese rival Xiaomi last week said first-half sales fell from the previous six months.

Industry-wide shipments in China, the world's biggest smartphone market, slipped in the first quarter for the first time in six years, researcher IDC said in May.