NEW YORK (AP) _ Television stations in five cities operated by the Sinclair Broadcast Group will switch affiliations in January from UPN to the WB network in an $84 million deal announced Monday.

The stations are WPTT in Pittsburgh, WNUV in Baltimore, WSTR in Cincinnati, KRRT in San Antonio and KOCB in Oklahoma City.

The deal may auger a switch in the balance of power between the two fledgling networks. The WB will become available in 87 percent of the nation's households, up from 82 percent, while UPN's coverage drops from 90 to 88 percent, the WB said.

The WB predicts, however, that the addition of such major-market cities could improve its Nielsen Media Research ratings by 10 percent and force a corresponding drop for UPN, WB spokesman Brad Turell said. During the most recent television season, UPN had a slight upper hand on its rival.

The network is counting on a ratings bump, with a corresponding improvement in the prices it can charge advertisers, to compensate for the $84 million it has agreed to pay Sinclair over a 10-year period.

UPN spokeswoman Penelope Levy said the network was confident the lost affiliates will be replaced by others in those markets.

The switchover for the five stations will take place on Jan. 16, 1998.

Sinclair stations in Milwaukee and Birmingham and Tuscaloosa, Ala., have extended affiliation agreements with the WB until 2008. An independent Sinclair station, WFBC in Greenville, S.C., will become an affiliate of the WB in November 1999.

The WB network is owned by Time Warner Inc.