Efficient Frontier Inc., a Mountain View, CA-based search marketing technology firm, has formed a strategic alliance with Vixia Inc., an e-mail marketing subsidiary of the Japanese conglomerate Mitsui & Co.

Mitsui has acquired an equity investment stake in Efficient Frontier under terms of the alliance. Efficient Frontier manages search-marketing spending on keywords for advertisers on Google and Yahoo.

"Our investment in Efficient Frontier is the first step toward bringing leading search engine marketing technology to the Japanese market and raising the bar for search overall," said in a statement Toshio Kanki, general manager of Internet service and marketing at Mitsui.