Finnish mobile handset manufacturer Nokia finally seems to have made some headway with long-term partner Microsoft. Nokia is planning to introduce two new Windows Phone 8 devices in association with Microsoft Sept. 5.

The two technology firms had a bitter face-off when Microsoft unveiled its tablet, the Surface, running on Windows 8 OS, provoking several of its long-term hardware partners. Though the Redmond giant dubbed its hardware venture as a design reference for its partners, Nokia, in particular, seemed to wonder how to supersede the Surface tablet, which comes with a superlative design.

The tablet war was widening the rift between Microsoft and its traditional partners. The software giant soon realized its folly and started announcing hardware partners for its OS versions. This seems to have assuaged some ruffled feathers.

The Nokia-Microsoft Sept. 5 event, viewed against the tablet background, shows how Microsoft is making attempts to keep its traditional partners in good spirits for its tablet and smartphone aspirations. The event is likely to raise the curtains off "Arrow" and "Phi" Windows Phone 8 handsets from Nokia.

Belonging to the Nokia Lumia range, the "Arrow" and "Phi" are claimed to be temporary names of the handsets, the Verge reported.

AT&T, the nation's second biggest telecom carrier, is planning to stock Nokia's "Phi" handset as an exclusive device while "Arrow" is likely to be made available with both AT&T and T-Mobile in the U.S.

The "Phi" is likely to sport a large curved glass display as successor to Lumia 800 and 900 range, complete with a polycarbonate body, according to the Verge.

A variant "Atlas" that may bear some semblance to "Arrow" is likely to be unveiled later in the year and marketed along with Verizon network.

Though the prototype of the handsets and parts of the Windows Phone 8 handsets have leaked on the Internet, the final design of "Arrow," and "Phi" are most likely to be unveiled at the Sept. 5 event.