NEW YORK — Fueled by political campaigns, TV ad spending climbed 10% in the fourth quarter and 12% for 1996, according to new figures released Wednesday by the Television Bureau of Advertising.In the fourth quarter, local TV spending won the bulk of increased election activity, with spending up 10% to $1.81 billion. Spot TV rose 9% to $1.88 billion, and national syndication was down 6%, to $668 million. Network TV climbed a healthy 13%, to $3.74 billion, TVB said. But the latter two categories were affected by reclassifying the WB and UPN weblets from the syndication category to network in 1996, influencing prior-year comparisons. For the full year, network spending rose 19%, to $12.4 billion, local TV was up 8% to $6.61 billion, spot TV climbed 7% to $6.59 billion and national syndication, with the weblets removed, was flat at $2.32 billion. Total spending came in at $27.91 billion, for the 12% gain. With politics and Olympics fueling 1996 gains, top ad categories like automotive and package goods, along with movies, will determine the TV ad market’s health this year.