Indra Nooyi, who is due to become chairperson of $32 billion Pespsico in May, is stepping down from the board of directors of phone manufacturer Motorola.

She, along with another director Laurance Fuller, informed the company that they would not stand for re-election but serve on the board until May 7 when Motorola's annual general meeting is scheduled to be held.

Motorola currently has a 13-member board and with the stepping down of the two, its strength is likely to be reduced to 11.

Nooyi, 51, gave additional responsibilities as the reason for stepping down. But media reports linked her decision to billionaire investor Carl Icahn taking a stake in Motorola with the aim of accelerating shares buyback.