On Monday, Dimension Data Holding, a network services and e-commerce shop incorporated in England and Wales, made an offer to purchase all shares of Proxicom, the struggling Reston, Va.-based interactive agency. The bid exceeded an offer made by the Compaq Computer Corporation last Thursday by 30 percent, offering $7.50 per share to acquire. Compaq's offer is $5.75 per share, or $266 million. Proxicom has yet to notify Compaq whether or not it will accept the Dimension Data bid. If Proxicom elects to move forward with Dimension Data, Compaq would have three business days to counteroffer.