Online shopping service Respond.com today announced a $45 million round of financing led by Morgan Stanley Dean Witter Venture Partners. The Redwood City, Calif.-based company will use the investment to expand operations internationally and build sales and marketing resources. Other investors include Access Technology Partners, Amerindo Capital Management, Attractor Investments, Index Ventures. The Barksdale Group, Hummer Winblad Venture Partners and Benchmark Capital are initial investors in the online store. Bill Harding of Morgan Stanley also will join Respond.com's board of directors.