eBay

(EBAY) - Get Report

and

Microsoft

(MSFT) - Get Report

said Monday they have joined in a technology-sharing and promotion alliance.

eBay, which is based in San Jose, Calif., will support Microsoft's .NET Internet strategy and will be one of the first Web sites to offer its commerce engine to Web developers as an XML-based Web service. Microsoft will integrate eBay into its Web properties

Microsoft Network

and

WebTV

. Finally, eBay will use Microsoft server technology in its operations.

Financial terms were not disclosed.

Shares of Microsoft were down $2.69, or 4.7%, to $54 in recent

Nasdaq

trading, which eBay shares were off 25 cents, or 0.7%, to $33.75.