WASHINGTON  Bankers have all but given up on defeating one of the most contentious provisions in the financial regulation bill  one that would effectively bar federally insured banks from trading for their own accounts  and are now focusing on battles like heading off a prohibition on derivatives trading.

As House and Senate negotiators head into a final push to send the legislation to President Obama, they have largely agreed to stricter limits on so-called proprietary trading than those envisioned in the versions passed by either chamber.

That outcome would be a victory for the White House and for the provision’s most dogged advocate, Paul A. Volcker, the former Federal Reserve chairman.

But with the so-called Volcker Rule now likely to become law after appearing to be dead at earlier points in the legislative process, banks are battling hard to fend off further restrictions on their activities.