Americans reached for their credit cards with gusto in May after an April lull, sending overall U.S. consumer borrowing up by $12.90 billion -- more than twice the forecast rise, a Federal Reserve Board report showed on Monday.

May consumer credit rose at a 6.4 percent annual rate in May, and credit outstanding totaled $2.441 trillion. Wall Street economists polled by Reuters had forecast a May increase of $6.0 billion.

The May jump was back on the pace of March's increase of $12.94 billion. April's gain was much smaller at a revised $2.29 billion, initially reported as a $2.60 billion increase.

May revolving credit, made up of credit and charge card debt, rose $7.25 billion, or at a 9.8 percent rate, to $894.80 billion, marking the biggest increase since November 2006.

May non-revolving credit, comprising closed-end consumer loans for purchases like cars, boats, college educations and holidays, rose $5.65 billion, or 4.4 percent, to $1.545 trillion.