Google already cut 4,000 jobs from the Motorola Mobility team, but a new regulatory filing suggests that might not be the end of the cutbacks.
"Motorola continues to evaluate its plans and further restructuring actions may occur, which may cause Google to incur additional restructuring charges, some of which may be significant," Google said in a filing with the SEC.
The search giant provided details on how much the layoffs will cost. That includes $300 million (£185 million) in severance-related charges, and $90 million (£56 million) in facility and market exit charges. Much of that will be recognised in the third quarter of 2012, but a portion will roll into 2013, Google said.
A company spokeswoman said that the filing was made "to provide updated information around Motorola Mobility's cost reductions that were announced earlier this summer," but provided no further details about additional costs or more job cuts.
In July, Google reported a jump in revenue since its Motorola acquisition was finalised – Google earned $12.21 billion (£7.5 billion) in the last quarter, up 35 per cent from the same time last year. Motorola's earnings reached $1.25 billion (£772 million).
The $12.5 billion (£7.7 billion) acquisition was cleared in late May, adding 20,293 employees and a mobile device hardware business to Google's already-successful Android operating system.
A month after the deal closed, the Federal Trade Commission reportedly began investigating Google over patent abuse charges related to Motorola, which was accused of not making good faith efforts to license its technology to rivals like Apple and Microsoft.
During the summer's revenue call, Google execs said it was too early to comment on future changes for Motorola, but a month later announced massive job cuts and the closing of about one-third of its production facilities. The majority of the layoffs impacted workers outside of the US, Google said in August.
The changes, a Securities and Exchange Commission filing said, were designed to return Motorola's mobile devices unit to profitability, after losing money in 14 of the last 16 quarters. "That said, investors should expect to see significant revenue variability for Motorola for several quarters," the filing said.
At the time, Google predicted that "generous severance packages" would likely cost the company about $275 million (£170 million).