UK firms should have greater ability to defend themselves from hostile takeover bids, the Takeover Panel has proposed.
Its conclusion follows a review of existing regulation in light of UK confectioner Cadbury being bought by US group Kraft Foods in February.
The Takeover Panel, the independent body that regulates takeovers, recommends new measures such as bidders having to reveal their financing plans.
It said its code needed changing to remove bidders' "tactical advantage".
However, it ruled out two of the most radical suggested changes put forward.
These suggestions were raising the threshold for a successful bid above the current 50% plus one of the target firm's shareholders, and removing the voting rights of individuals or groups who bought shares in the target firm following the start of the bidding process.
The Takeover Panel said these moves had been "unanimously rejected" during its consultation, and were "impractical".
Instead, its other proposed changes include requiring bidders to clarify their intentions within a shorter time frame, and improving the ability of workers at the target firm to make their views known.
The review was carried out by the Takeover Panel's rule-setting Code Committee.
Lindsay Tomlinson, chair of the committee, said: "It is clear that some rebalancing of the rules is needed to check the evolution of market practice which has run in favour of the offeror.
"We will propose proportionate measures to do this, which do not require changes to law or compromise shareholders' rights."
The CBI business organisation welcomed the Takeover Panel's proposals, saying they would "reduce periods of uncertainty for companies that are takeover targets".