Mobile telecom equipment maker Ericsson has plunged to a quarterly operating loss, hit by shrinking markets and restructuring costs. 

The Swedish company is focusing on its core networks business under new chief executive Borje Ekholm.

It reported an operating loss of 12.3 billion Swedish crowns ($1.4 billion) as previously announced provisions, writedowns and restructuring costs pushed it deep into the red. 

That compared with a 3.5 billion crown profit in the same period last year and a mean forecast for a 12.billion crown loss in a Reuters poll of analysts. 

Ericsson has been hit by a drop in spending by telecoms firms, with demand for next-generation 5G technology still years away, and weak emerging markets.

It also faces mounting competition from China's Huawei and Finland's Nokia. 

The company said its first-quarter sales came in at 46.4 billion crowns, below the consensus forecast of 47.3 billion, while the gross margin was 13.9% compared to the 17.9% seen by analysts. 

Ericsson said industry trends from 2016 were expected to continue in 2017. It has forecast the mobile infrastructure market to decline by 2-6% this year and stabilise thereafter.

Ericsson announced $1.7 billion in provisions, writedowns and restructuring costs at the end of March. 

Analysts have said these may have been related to emerging markets such as Russia, China and Latin America, as well as US mobile operator Sprint, which renegotiated a managed services contract with Ericsson in July.