WASHINGTON — President Barack Obama is nominating a top Treasury Department official to run the independent agency that regulates the futures and options market.

The White House says Obama later today will announce the nomination of Timothy Massad to head the Commodity Futures Trading Commission. For the past three years, Massad has overseen the Troubled Asset Relief Program, the bank rescue plan known as TARP.

Obama is expected to use Massad’s nominating ceremony to call on Congress to fully fund the CFTC, one of the smallest and most thinly funded U.S. agencies. Obama’s 2010 financial overhaul law gave the agency the task of laying down rules for oversight of derivatives, the complex instruments traded in a $700 trillion worldwide market that has been unregulated.

The agency has now completed 43 of the 60 rules it was charged with putting into motion under the overhaul law.

For the CFTC, some of the thorniest and most critical rules are among those that remain. They include the so-called Volcker Rule, which would prohibit banks from trading for their own profit.

Adoption of the rule has been delayed largely because of Wall Street banks’ objections and the need to get a handful of federal agencies, including the CFTC, to agree on its final form.