Mobile phone giant Ericsson is taking legal action against a Birmingham company after accusing it of using its technology without paying for it.
The Swedish corporation claims Birmingham-based handset manufacturer Sendo has infringed patents of its latest GSM and GPRS technologies.
The writs come just months after Sendo successfully sued computer giant Microsoft, which it claimed had sold its ideas to companies in the Far East without permission.
Ericsson spokesman Kasim Alfalahi said the company had been forced to take the matter to court.
"We believe that Sendo is using Ericsson patented technology, but they have so far not signed a license agreement with Ericsson. Under these circumstances we have no choice but to take Sendo to court," he said.
However, Sendo's founder Hugh Brogan claimed such accusations were " unprovoked and unnecessary".
He said: " Sendo have already concluded a number of licensing agreements with various companies and are open to signing an agreement with Ericsson as soon as possible provided that their terms are fair and reasonable.
"Up to this point they have not met with this criteria."
He said Sendo had previously filed a complaint against the terms of Ericsson's patent licensing programme to the European Competition Commission.
"We will defend ourselves vigorously against such bullying," he added.
The small privately-owned company employs 350 people worldwide, 220 of whom are based in the West Midlands, with an annual turnover of $400 million, making them one of the leading handset manufacturers in the UK.