Japanese electronics firm Panasonic has nearly doubled its projected net loss for 2011 to ¥780bn (£6.47bn) – the biggest in the company's 95-year history – as the global economic crisis dampens demand for TVs and mobile phones.

Panasonic reported a net loss of ¥197.6bn in the three months to December, following "significant sales declines" and ongoing restructuring costs following its purchase of Sanyo Electronics in 2009.

The company's grim outlook mirrors that of fellow Japanese electronics firm Sony, which on Thursday warned that annual losses would be almost twice as bad as forecast.

The embattled electronics companies have been hard hit by weakening demand for TVs, a strong yen, and lower production following the Thailand floods.

In October Panasonic forecast losses for the year to March of ¥480bn, but its revised estimate of a ¥780bn net loss (in the year to March 2012) would eclipse the company's previous worst full year loss of ¥427bn in 2002.

The company said sales fell 14% in the three months to December 2011 to ¥1.96bn, compared with ¥2.28bn in the final quarter of 2010. The fall contributed to a net loss of ¥197.6bn in the final quarter of last year, compared with a ¥40bn net profit in the three months to December 2010.

"The primary causes of this are the global economic slowdown and instability in the financial markets due to the European debt crisis, as well as the extensive supply chain disruption caused by the flooding in Thailand that occurred in October 2011," Panasonic said in a statement.

Sales of flat-panel TVs and mobile phones plummeted in the period, although sales of PCs and some home appliances enjoyed a small boost.

Panasonic moved to shake up its business following the purchase of Sanyo Electronics, including revamping its TV and chip operation and cutting jobs.

"At the core of our latest restructuring was to make our TV unit profitable," said the Panasonic president Fumio Ohtsubo on Friday. "Panasonic's TVs may one day be a case study of a recovery."

On Thursday Sony reported a ¥159bn net loss between October and December as sales fell 17% in a festive period that would usually bring a boost for consumer electronics. Sony increased its forecast loss for the 12 months to March to ¥220bn; in November it had predicted a loss of ¥90bn.

The results proved the scale of the challenge ahead for Kazuo Hirai, who will take over as Sony chief executive in April after Sir Howard Stringer announced he was to step aside.

Both Panasonic and Sony are in fierce competition with South Korean rival Samsung in the TV market, where prices have tumbled in the past year. Panasonic remains the

fourth-biggest TV maker in the world.

Far eastern electronics firms are still grappling to recover from the Thai floods in October last year, when many companies were forced to halt production at key manufacturing hubs in the region.