Cellphone maker Nokia and browser firm Opera Software pledged on Thursday to support Adobe Systems' Flash software in its bitter row with Apple.

Apple Chief Executive Steve Jobs last month slammed Adobe's Flash multimedia software, which is used in most smartphones, calling it unreliable and ill-suited for mobile devices, escalating a pitched battle between the two firms.

Jon von Tetzchner, co-founder of Opera -- the maker of most widely used cellphone browser and strong supporter of open Internet initiatives -- said on Thursday his company was supporting Flash.

It is the only proprietary part of the Web we support, von Tetzchner told Open Mobile Summit conference in London.

We support Flash as well, said Alberto Torres, chief of Nokia's solutions business unit.

Flash-based video and games are found on many Internet sites, but Apple has not allowed Flash on its iPhone and iPad.

The hostility between Apple and Adobe has been brewing for months. Apple has criticized Flash as a buggy battery hog, while Adobe has accused Apple of exerting tyrannical control over developers creating programs for the iPhone and iPad.

The rhetoric has grown ever more heated. In April, Flash platform evangelist Lee Brimelow ended a blog post by saying, Go screw yourself Apple.

(Reporting by Tarmo Virki; Editing by Steve Orlofsky)

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