Microsoft has rebuffed a complaint from UK mobile phone maker Sendo, which had accused the software giant of planning to plunder its trade secrets.

SENDO

Founded in 1999 Britain's only mobile manufacturer Makes non-branded phones for operators such as Virgin Sells in 20 countries; now eyeing US market

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Birmingham-based Sendo sued Microsoft last December in a Texas court, after the two firms ditched an agreement to develop jointly multimedia mobile devices.

Sendo switched to Nokia as a technology partner, after fears that Microsoft was passing its intellectual property on to rival mobile makers.

Now, Microsoft has flatly rejected the accusation, and countered with the charge that Sendo had "consistently failed to meet its contractual obligations to design and develop" its now-defunct Z100 phone by the agreed deadlines.

The US firm has asked that the case be dismissed.

Two systems

The case underlines Microsoft's troubles in promoting its Smartphone multimedia technology.

So far, only mobile operator Orange has launched a phone based on Microsoft Windows software.

The rival Symbian system, which originated with handheld computer firm Psion, has already spawned nine phones from three manufacturers.

The difference, analysts say, is that Symbian provides its software source code freely to its licensees, while Microsoft keeps its technology a closely-guarded secret.

Tit for tat

With so many accusations flying to and fro, the current case is likely to be acrimonious.

Aside from the allegations of plundering, Sendo had claimed that Microsoft failed to meet its financial obligations.

Microsoft, which took a minority stake in Sendo to underpin the original partnership, counters that Sendo repeatedly misled it as to its financial situation.

In documents submitted to the court, Microsoft said an anonymous Sendo employee had described Sendo's efforts to make the Z100 as a "runaway train".

The British firm was rushing ahead with a substandard and unreliable product, Microsoft argued.