HOLLYWOOD - In a deal that's expected to hit seven figures, three networks and at least one studio are actively bidding to lock up the services of former "Spin City" star Heather Locklear.
     While the TV biz has been cutting back on scribe and talent pacts lately, execs still are willing to shell out serious coin for talent with proven track records. And in Locklear's case, insiders are betting she easily will be able to snag a $1 million-plus holding deal and an understanding that she'll be able to headline her own show rather than serve as a supporting player.
     NBC, ABC and Fox are the webs that have made overtures to Locklear. On the studio side, Warner Bros. TV is said to be interested in the actress.
     One exec said it's no mystery why Locklear is generating so much interest: "She's been in three series and made them all work. And that doesn't even count 'T.J. Hooker.'"
     Indeed, before she "breathed new life into 'Spin City,"' as one exec put it, Locklear almost single-handedly turned Fox's "Melrose Place" into a pop-culture phenomenon. She also added zing to long-running soap "Dynasty."
     There's no timetable on when Locklear will make her decision, but industry insiders said a pact could easily close by month's end.