Companies vulnerable to cash tender offers by other firms are organizing defense teams to ward off potential takeovers, according to a study by the Conference Board.

Although tender offers - both cash and securities - still constitute only a small portion of the total mergers and acquisitions in the United States, the number of recorded tender offers has risen dramatically since 1960, the private business research organization said.

Only 7 offers were made in 1960. An estimated 62 cash tender offers occurred in 1968 and a record 113 in 1975 - a figure which may be exceeded this year, the board said.

A profile of the so-called "sleeping beauty" company ripe for takeover emerged from the board study. "Vulnerable firms usually have a low price-earnings ratio, a stock book value above the going market price, a limited number of shares outstanding, undervalued assets, a highly liquid financial position, unused borrowing capacity, and limited insider control," it said.

The corporate defense teams organized to fight takeover bids often consist of outside legal counsel, investment bankers, proxy solicitors and public relation experts, in addition to the chief executive officer, chief financial executive and top corporate attorney, the study found.

Some companies are making moves to reduce their vulnerability to unsolicited takeovers, the board said. For example, firms are reincorporating in states with laws on takeovers, reshaping their boards of directors, and imposing clauses that require more than majority approval for mergers and acquisitions.