A US judge on Tuesday granted a last-minute reprieve to Texas death row inmate Kimberly McCarthy, who had been scheduled to become the first woman executed in the United States since 2010.

McCarthy -- who has been on death row for 14 years -- had been due to be executed at 6:00 pm (2300 GMT) after the US Supreme Court rejected her final appeal, but was instead given a postponement of about two months.

"The trial court granted a motion to reset the date. It is now set April 3," her attorney, Wayne Huff, told AFP. The Texas Department of Criminal Justice confirmed the postponement, without offering an explanation.

McCarthy's lawyers had asked Texas Governor Rick Perry to issue a 30-day reprieve, arguing that racial bias had had an impact on the case.

McCarthy, 51, is black. Her victim, 70-year-old retired professor Dorothy Booth, was white.

"The unacceptable disparate impact of race on the administration of the death penalty in Texas has become increasingly well established," her lawyers wrote.

They noted that despite the fact that her home county is 22.5 percent black, only one non-white juror judged McCarthy and three non-whites jurors "were unilaterally excluded by the state despite being fully qualified to serve."

They further argued that 42 percent of people sentenced to death in Dallas county were black while 70 percent of the 24 men exonerated with DNA evidence in the same county were African Americans.

"A remedy is not only warranted, but demanded," her lawyers argued Monday.

McCarthy was set to be just the 13th woman executed since the death penalty was reinstated in the United States in 1976.

She was convicted of forcing her way into her elderly neighbor's home near Dallas under the pretext of borrowing some sugar in 1997, court records show.

She then smashed Booth in the face with a candle stick, stabbed her five times and cut off her finger to steal her diamond ring.

McCarthy drove off in Booth's Mercedes and tried to buy some crack, court documents showed. She also used Booth's credit cards at least four times and pawned her wedding ring for $200 before she was caught.

Prosecutors also accused her of killing two other elderly people.

She was sentenced to death in 1998, saw her conviction overturned on appeal and then was convicted and condemned again in a second trial in 2002.

"There's a good chance that she would not be sentenced to death if tried now," said Richard Dieter, director of the Death Penalty Information Center.

"A case like this involving apparent drug addiction and other mitigating factors might well have been settled without the death penalty."

Texas was sentencing as many as 40 people to death a year before the courts began providing juries with the alternative sentence of life without parole. That number has now since dropped to about eight people a year, Dieter said.

McCarthy would have been the fourth woman executed in Texas since 1976, out of a total of 493. Nine other women are among the 304 people on the state's death row.

A dozen women were among the 1,321 people executed since 1976, according to the Death Penalty Information Center. Of the 3,199 people on death row as of October 1, 63 were women and 42 percent were black.