Viacom Chairman and CEO Sumner Redstone said Tuesday he is “personally committed” to splitting his media empire into two companies and repeated his promise that Viacom would make a decision on a breakup sometime in the second quarter.

“I want all of you to know that I am personally committed to achieving this separation,” Mr. Redstone said during a conference call to discuss the company’s first-quarter business. “From our perspective, in order to maintain our leadership position … and fully exploit all of the opportunities we see, we envision two companies.”

The media giant several weeks ago confirmed Wall Street speculation that it was considering a breakup, with MTV Networks and Paramount Pictures combining to create a growth company while CBS, UPN and Infinity Radio join forces to create a company that generates large amounts of cash flow. The company said it would make a decision in the second quarter, with any transaction to be completed by the first quarter of 2006.

For the quarter, Viacom reported an 18 percent decline in profit to $585 million, compared with a year-earlier profit of $710.5 million, while revenue advanced 5 percent to $5.6 billion.

The revenue growth was driven largely by a 19 percent revenue jump at the company’s cable networks to $1.7 billion. The increase was largely the result of a 27 percent surge in advertising dollars, a 9 percent rise in affiliate fees and a 10 percent increase in ancillary revenues.

Meanwhile, Viacom’s television operation reported a 5 percent decline in revenue to $2.1 billion due to the absence of the Super Bowl in the 2005 quarter and lower political advertising and television licensing revenues.