SAN FRANCISCO (Reuters) -- Diversified U.S. chipmaker Marvell Technology Group Ltd (MRVL.O) gave a conservative outlook for the third quarter, sending shares lower, even after it posted better-than-expected profit helped by increased sales in the wireless and storage sectors.

Marvell, whose chips are used in Apple Inc's (AAPL.O) iPhone and Research In Motion Ltd's (RIM.TO) BlackBerry, said on Thursday it is still uncertain of the impact of the weakening U.S. economy and predicted revenue growth below Wall Street expectations.
""They had a strong quarter, which was widely expected, but the outlook was light,"" said John Dryden, analyst at Charter Equity Research.
The company reported second-quarter net income of $71.4 million, or 11 cents per share, compared with a net loss of $56.5 million, or 10 cents per share, in the year-ago period.
Revenue rose 28 percent to $842.6 million from $656.7 million a year earlier.
The results beat Wall Street analysts' average forecasts of non-GAAP profit of 21 cents a share and revenue of $836 million, according to Reuters Estimates.
""The results for our second quarter were better than we had anticipated,"" Sehat Sutardja, Marvell chairman and chief executive officer, said in a statement.
Marvell said profit was helped by strong revenue growth across its range of products led by wireless and storage products.
Marvell Chief Financial Officer Clyde Hosein told Reuters the company was been ""cautious"" with its outlook because of uncertainty with the weakening U.S. economy.