Sen. Charles S. Robb (D-Va.) heads into a costly reelection fight next year with his family's Texas-based wealth intact and available, annual Senate financial disclosure statements showed yesterday.

Otherwise, it was a modest year in the region as Sen. Barbara A. Mikulski (D-Md.) dabbled in the stock market and Sen. Paul S. Sarbanes (D-Md.) hung onto one of the Senate's leanest portfolios despite his status as ranking Democrat on the Senate banking committee.

Sen. John W. Warner (R-Va.) received a 90-day extension from the Select Ethics Committee for his filing, which was due May 17.

Robb, like Warner a multimillionaire, reported more than $6.3 million in assets, most of which are held by his wife, Lynda Johnson Robb, and their three daughters. The family's outside income of at least $2.6 million--drawn from annuities, trusts and the Pedernales Partnership, a Texas land company--dwarfed his $136,700 annual Senate salary.

Robb's share of the family wealth was between $600,000 and $1.5 million. Lynda Robb, one of the late President Lyndon B. Johnson's two daughters, holds at least $4 million in trust and in real estate in Texas, Alabama and Oklahoma, including a 25 percent share of the LBJ Ranch in the Texas Hill Country. Jennifer Robb, their youngest child and sole remaining dependent, owns $1.7 million.

Congressional disclosure rules require senators to report assets and liabilities only within broad ranges, making net worths unclear. Family members face looser rules, so actual holdings could be higher.

Lynda Robb, for example, reported holding more than $1 million each in a Morgan Stanley Dean Witter money market account and in a blind trust, and her daughter, Jennifer, more than $1 million in Three Sisters Blind Trust. There is no upper reporting range for assets held independently by a spouse or child.

Sen. Robb also disclosed reimbursement for one trip to Abingdon in Southwest Virginia for a speech to the United Mine Workers of America.

Robb, rarely one to pour his own money into his campaigns, is racing to build a war chest for an expected faceoff next year against former Republican governor George Allen.

In Maryland, Mikulski reported $173,018 to $630,000 in assets in nearly two dozen stock, bond, pension, money market and bank accounts. That's a jump of at least $17,000 from last year, which may reflect her increased activity in the stock market.

Mikulski bought and sold between $15,000 and $50,000 worth of shares in Rydex Series' Nova and Ursa funds--aggressive market-timing bear-and-bull funds--seven times between May 18 and Oct. 28.

She also received $10,502 in royalties and movie advances from two mystery novels she cowrote in 1996 and 1997, and donated $1,000 she was paid for speaking at Anne Arundel Community College. She traveled to West Virginia's Greenbrier Resort in May as a guest speaker for Zeneca Pharmaceuticals, maker of the breast cancer drug tamoxifen.

Sarbanes reported 1998 assets that were little changed from the year before. He disclosed owning $167,000 to $430,000, split among his Baltimore home, Senate credit union, bank, insurance policy and state retirement accounts.