* America Online of Dulles said it signed leases for two new office buildings near its headquarters, with a total of 154,000 square feet of space. The online services company moved 100 employees into one partially leased building this month and plans to move 400 to 500 employees into the second building in December. AOL already owns 1.2 million square feet of office space at its headquarters and occupies a number of other buildings in Northern Virginia, but it wanted the flexibility of additional leased space, said Nicholas Graham, a spokesman for the company. AOL, which employs about 4,700 people in the Washington area, will have the option of renewing one of the new leases next year, he said, while the other lease is for seven years. Graham declined to comment on the value of the leases or whether AOL plans to hire additional employees.

* PEC Solutions of Fairfax, a technology services firm that specializes in government contracting, won a subcontract from the Department of Veterans Affairs to provide information technology services. PEC, which will be a subcontractor to Science Applications International, will provide services related to Microsoft network and systems engineering. Terms of the contract were not disclosed.

* New Enterprise Associates of Baltimore, a venture capital firm, has invested $40 million more in Vonage Holdings of Edison, N.J. NEA, which also has offices in Reston, led the current $105 million round of financing, bringing the total investment in Vonage to more than $200 million. Vonage, which provides telephone service to consumers and small businesses over the Internet, will use the funds to accelerate expansion of service in the United States and abroad and to support development of new product offerings.