Roche Holding said it planned a major review of its operations and would take steps to reduce its operating costs.
That is in contrast to a similar relationship between Roche Holding and Genentech.
Roche Holding reported its first-quarter revenue was up 5 percent, to $4.4 billion, less than market expectations.
The company bought a considerable stake in Roche Holding.
A spokesman for Roche Holding said the company was cooperating, but declined further comment.
Roche Holding of Switzerland said its profit increased 14 percent, to $3 billion last year.
The biotechnology company is developing a drug to combat obesity in a venture with Roche Holding.
Roche Holding said sales in the first nine months of the year rose 7.5 percent, to $11.4 billion, helped by increased demand for diagnostic tests.
Roche Holding posted a 4 percent decline, to $2.8 billion, in its net profit for 2001, as its investment income fell.
Roche Holding will report results next month.